Based on your other posts, you're either a fervent Blizzard fan or just a trolling ass. You can't call people fanboys when all you do is insult and hate on people that don't love Blizzard.
Furthermore, DotA wasn't made by the "Blizzard Community". It was played by and slightly modded by a part of the community. The game/mod itself was made by a small handful of people, one of whom (that being IceFrog, who was basically handed the franchise by the other two creators after they left to pursue other projects) now works at Valve. Frankly, it's within Valve's right to trademark the name. The only reason people like you are bitching is because you somehow think you'll have to buy the game and won't be able to mod it. Clearly, you've not really read up on the topic. The game is likely going to be free, just as Alien Swarm was. It will allow (and provide support for) any and all modders within the community. Just as they've done with Team Fortress 2 and Left 4 Dead. And, just like all of Valve's games, it will receive frequent, free updates and content. Blizzard does the same, mostly, but unlike Valve, they usually charge for any large content update. (I point you to World of Warcraft, specifically) Now that's disgusting.
This all comes down to a community assuming it owns a game. It'd be like if the Team Fortress 2 community decided Valve has no right to own the brand or do anything with it because it's "theirs". The community plays it, so clearly it must belong to the community! Self-entitled whiners ruin everything, I swear. This whole fiasco is as bad as the whole Left 4 Dead 2 boycott. (if not worse, since it's not just a whiny bunch of kids but an high-profile company doing the whining)