that's because the gaming market isn't basement dwellers playing the latest shooter or hack and slash game. it has moved way beyond that now. angry birds and other casual games hook people that would never play "real games" and they make more profits than most "real games"
Your right there's no need to make any big 'nerdy' games when there's a fortune to be made from casual angry birds clones. The problem is that developing these mobile casual games is basically a lottery where millions play and only a few very lucky people ever actually the big money.