If apps only sell for a dollar, developers will only make apps that are worth one dollar. That could end up being a problem for the software industry in general. If the best developers, who could be improving our operating systems or writing better productivity software are all trying to replicate the success of the latest mobile app instead, then the lure of the app marketplace will actually stagnate the entire industry. Instead of working in teams for companies who need good software to do a better job, they'll be working alone and trying to grab their slice of the pie, $1 at a time.
Mokalus of Borg
PS - And when the app bubble bursts and they come back, nobody will know how to work in teams any more.
PPS - Or this might just be irrelevant hand-wringing and everything will be fine.