Craftworld Eldar in the rumormill

[Charon]

But is it anyone's arguments they don't also struggle against significantly optimized marine, necron, or tau armies?

Against significantly optimzed armies? Sure. Against "just strong" or "average builds"? The odds are still against you but not so bad that I would use the word "pointless" or "hardly winnable" as you still have a mobility advantage in most cases and can just play to the mission.
Sadly even an average Eldar army negates the mobility advantage, they outgun and outsustain you while costing less points.
And that is a huge difference between struggling vs highly optimized armies or struggle against any build of that army. I can't think of reasonable eldar build (that is if you do not intend to 1500 points of guardians) that is not able to just blow an optimized DE army out of the water.
I do play both for a long time now and I am very confident in my DE play (less so in my Eldar play) but I really struggle to see any bright side in this.

The most hilarious thing I heard on the Dark City was something like "Omg imagine the horror when we drop Wraithguard with an Archon and WWP, Banshees in Raiders which cant be shot, Psykers with all the -Ld we can bring,..." "You can be sure if we do this they will nerf our stuff in the next codex because it is too good when combined with eldar"

Yeah, Dark Eldar lost a couple of old tricks. But you have to be insane (or trolling) to claim they're somehow below Orks.

the biggest declines going to Dark Eldar and Blood Angels. Meanwhile, Orks and Chaos Space Marines did significantly better than their track record, with 11.8% and 7.8% improvements respectively.

So how do you jump to this conclusion when you bring the data yourself?
The decline from dark eldar is the point where the new codex hit. So is improvement of orks. Given the fact that most orks went with 3 FOC and green Tide. The ork codex is actually an (power) improvement. It may be less flavorful and some units are absolutely useless, but the overall power if optimized has gone up.
While the Dark Eldar codex not only stripped flavor (wtf only 3 SC survived the purge... not even a faction leader) and did nothing for the power level, quite the opposite.

[Erik Setzer]

Given the fact that most orks went with 3 FOC and green Tide. The ork codex is actually an (power) improvement. It may be less flavorful and some units are absolutely useless, but the overall power if optimized has gone up.

Yay! Orks went from being utter crap to just mediocre! HUZZAH FOR IMPROVEMENT!!!

I've played both. I love my Orks, but Dark Eldar *are* better. And no, a Green Tide doesn't make an Ork army good. It just means you're putting a lot of bodies on the table that can't maneuver well, will likely bog down if there's any amount of terrain, and provide glorious targets for templates, tying up at least 800+ points into one unit. BRILLIANT! It's a freaking genius idea! So genius that I saw a guy use it over the weekend against Space Wolves and lose, especially as they were playing with objectives, and that massive horde of Orks is hard to reposition for taking objectives. Bonus, if you try to charge more than one unit with it, you lose not only the +1 Attack, but also Furious Charge, meaning you negate the only thing really making Orks okay in combat (for one turn). But if you're not charging multiple things, you're wasting a lot of bodies. Oh, but your opponent can charge you with multiple units who *will* get their bonuses for charging. Yep, yep, I just can't see why people don't always take a Green Tide! Sure, it can't maneuver, it's easy to smash with templates, it makes assaulting even more worthless, it's a lot easier to assault, it can't attack multiple targets... but it's a lot of Orks in one spot taking up over half your army's points, so that's game-changingly-powerful! Next to that, how can an army full to the gills with Poison, Lance, and Haywire weapons compete?

Hey, uh, do you want me to keep going with this? Because I totally can. I'm sure I have more mocking left in me. And the claim that the Green Tide is a "competitive" formation is worth mocking.

Or we could just go back to talking Eldar.

[Tzeentch's Dark Agent]

Groan, I can't read this many complicated Spanish phrases.

[Charon]

Yay! Orks went from being utter crap to just mediocre! HUZZAH FOR IMPROVEMENT!!!

I've played both. I love my Orks, but Dark Eldar *are* better. And no, a Green Tide doesn't make an Ork army good. It just means you're putting a lot of bodies on the table that can't maneuver well, will likely bog down if there's any amount of terrain, and provide glorious targets for templates, tying up at least 800+ points into one unit. BRILLIANT! It's a freaking genius idea! So genius that I saw a guy use it over the weekend against Space Wolves and lose, especially as they were playing with objectives, and that massive horde of Orks is hard to reposition for taking objectives. Bonus, if you try to charge more than one unit with it, you lose not only the +1 Attack, but also Furious Charge, meaning you negate the only thing really making Orks okay in combat (for one turn). But if you're not charging multiple things, you're wasting a lot of bodies. Oh, but your opponent can charge you with multiple units who *will* get their bonuses for charging. Yep, yep, I just can't see why people don't always take a Green Tide! Sure, it can't maneuver, it's easy to smash with templates, it makes assaulting even more worthless, it's a lot easier to assault, it can't attack multiple targets... but it's a lot of Orks in one spot taking up over half your army's points, so that's game-changingly-powerful! Next to that, how can an army full to the gills with Poison, Lance, and Haywire weapons compete?

Hey, uh, do you want me to keep going with this? Because I totally can. I'm sure I have more mocking left in me. And the claim that the Green Tide is a "competitive" formation is worth mocking.

Or we could just go back to talking Eldar.

Did you ever consider that you are just a lower than average player?
You are no benchmark. Not in the slightest.
And I can't even begin to understand how I never heard of the successful tournament player that you obviously are. Because otherwise I see no validity in your claim that green tide is not competitive when Orc players at big international events prove otherwise.

[Mr Mystery]

Yep.

[Thaldin]

I just want my new codex to play with the only army I have ever owned since 1991ish against my friends who also enjoy playing =\

[Morachi]

Looks like my annual leave at work is going to take a hit. It will be a month of Sunday's before I can put the full 101k of Warhost into allocated formations all over again O_o ahh 1st world problems.

[Mr Mystery]

I just want my new codex to play with the only army I have ever owned since 1991ish against my friends who also enjoy playing =\

'Kin-a dude!

[Arkhan Land]

Groan, I can't read this many complicated Spanish phrases.

I Can!

[Defenestratus]

Looks like my annual leave at work is going to take a hit. It will be a month of Sunday's before I can put the full 101k of Warhost into allocated formations all over again O_o ahh 1st world problems.

Morachi - my arch nemesis. The only person on earth that I can't alpha-nerd with my Eldar collection.