Well, everyone has their opinion, but yours is pretty retarded. I'd say it was SC2 that killed WC3.
1) DotA is a dumbed-down RTS.
1a) DotA players argue that it has a leg up on RTS because DotA games require teamwork. These people have not played any other RTS other than StarCraft, where team games utterly suck.
1b) DotA is an RTS with one map.
2) In becoming a dumbed-down RTS, it finds much in common with MMO and Action-RPG games which are (unbelievably) more complex in most regards.
3) The combat interactions are absolutely pathetic when compared to similar genres which require excellent pattern recognition skills (fighting games, beat 'em ups).
4) The genre greatly rewards knowledge-based depth (understanding skills and abilities) over functional depth (using those skills and abilities) and that learning curve is what makes the game appealing to weaker players, since information osmosis will inevitably make the player better through the early ranks.
5) The game's audiovisual component is largely lacking, because it has been shaped by a budget-cutting, low-poly cartoon style which allows for the quick, cheap, and disposable creation of new artwork that will fund the free-to-play game model.
5a) Most of the sensory and visual feedback in the game is generated by "numbers going up" and "how much damage was done", since items almost never provide any sensory (audiovisual) feedback
6) The genre lacks depth to the point where its creators create the illusion of depth with regular patches, tweaking numbers on a monthly and even bi-monthly basis to create the illusion of an evolving metagame
7) Character templates are normalized and standardized (i.e. have no significant deviation from each other) because the development model requires creators to introduce new characters as time passes. If this was done in fighting games, for instance, it would destabilize and potentially break a carefully-balanced and designed roster.