A guy is in into dota because
1. Its either because the game is played widely in this country, they want to blend in (eg: almost anywhere u can see teenagers talking about that game)
2. because he enjoys the pleasure of killing, showing off when he is so damn kao good.(eg: show off in frt of his girl friend)

I dun think girls will intrude into ur personal gaming life, i play counter strike, and she dun mind