This thread does what it says on the tin: why the hate?

The context is important here.

For one thing, I have recently started a Blood Ravens army, using the vanilla Marines codex as my basis (I don't think they need a codex of their own, but if the rumors are true, I really hope they get a banner in the new Marines codex). When I tell people that my previous armies are Tau and Blood Ravens, I tend to get a negative reaction, as though I've somehow given up on playing an army that is unique, cool, and fair in order to be competitive.

The thing is, most of the Marines chapters seem to have pretty cool stories, and power armor can be fun to paint, with all its little bits and bobs and decorations.

Secondly, I just played my first two games with my new army, and it was an interesting experience. I don't feel like my new models are "easy-button" or anything like that. In fact, in some ways they were extremely challenging, and not just because they were new. Without a strong focus on any one thing, the way Orks and Tyranids focus on assault, Blood Angels focus on maneuverability, or Imperial Guard and Tau focus on shooting, I had to be very careful and tactical in order to achieve anything. The unusually high durability of my troops was actually a pretty thin compensation for the lack of specialization. My dudes needed to be tough, because I didn't have a ton of them, they didn't drop out of the sky, they have mediocre strength weapons, and they don't kill everything in assault.

Based on my experiences, I have to wonder... where's the hate from? Why do people seem to dislike the Marines as a faction?