I don't want a *RAIDER* because I don't want to take DE allies. It has nothing to do with CAD, effectiveness, or anything else. If there was an Eldar version of the raider I'd gladly take it without hesitation. I don't like DE. I don't like their aesthetic. I don't like their fluff. I don't like their models, and perhaps my most hated model is the raider. So I don't want to take the assault vehicle that I legally can because its not part of my f*cking army. Plus, if I'm allying, why the hell would I ally with DE for close assault support? There are much better allies out there to fill that role - like terminators in a Stormfang/Raven/FW Ram thingie.
It makes perfect sense. Eldar are an endangered species who value each single individual above that of entire planets of aliens... they have the most advanced technology in the galaxy and have been around the longest, yet their tanks aren't capable of propelling their warrior into combat? Makes a whole lot of sense, fluff wise, to have a vehicle that could protect their deadliest close combat warriors while delivering them to where they're needed the most. Hell, the Eldar army is built off of synergy between units - unfortunately there's no synergy to be had that will absolve the banshees of being made of paper mache.So, basically, there's Eldar players wanting an upgrade that makes absolutely zero sense, and they can't even defend the idea (because it makes no bloody sense, which they'll admit if you sub in another army).
Plus, our tanks aren't even comparable to rhinos. They're more in line with the cost of a predator thats been upgraded, but lets not stop comparing apples to oranges.