[dragonwriter]

> It's a little naive on Google's part to assume people will create AND maintain tons of useful, quality applications just out of sheer enjoyment or the goodness of their hearts.

Google doesn't assume that. Google knows that Glass's feature set is only useful to provide auxiliary functionality for multi-device services, and they expect that users experience will be better if you pay for the multidevice service but not separately for the Glass app.

I'm sure they expect that the people making useful, quality Glass apps will often be making plenty of money from the services those apps interact with, not doing it out of either "sheer enjoyment" or "the goodness of their hearts."