Dota is pretty fun, sometimes ( a lot of the time) there are players in the game with you that have a shitty attitude and thats mostly why it gets such a bad rep, that coupled with the vertical learning curve. But w/e a lot of games have a bad community, and there are AI maps to practice on before you go live if you want to avoid some flack. Overall I like it a lot, but I do wish there was some competition / or just more quality maps.
And I agree with you about the halo /counterstrike thing. Just like I don't think dota is a rip-off. People get to worked up about that kinda stuff. With there mindset nigh everything they do/play is a ripoff.
You avoid the plu-part of the bad community by joining up elsewhere than flame-heaven, ie BNet. DotA-League is also bad, so don't bring it up.. please. Just practice and ignore flames and make your way either to VIP SIG (DotA-League quality-ensured ladder) or to an inhouse league, where you are valuated before you enter the real games, and kicked out later for bad attitude or game ruin/lack of skill. Personally I play in DCE, and I'm very satisfied with that. Even I get flamed on BNet, simply because noobs flame everyone and call everyone noobs- if you kill them, you're a noob, if you die to them, you're a noob, if you build something else than Sange & Yasha, you're a noob, if you deny, you're a noob, if you farm better than them, you're a noob, if you lane with Axe, you're a noob. All but the two first indicate possible skill, but in the eyes of a noob, who have learned from noobs that has been in the business longer, you play different and act friendly, so you're a noob (because they're definately not noobs at all, no!, they're pros and pros have attitude, according to them).
Pardon the long sentences where it is easy to get lost. And before you start flaming, I'm not claiming to be pro, I'm just not a noob (at DotA).