I can see the benefit Google gains from increased usage of plain text - but I can't see how this can be a main driver for their decision to launch this platform

I can see the benefit Google gains from increased usage of plain text - but I can't see how this can be a main driver for their decision to launch this platform. The web is progressing towards native support of @font-face. This is an intermediate step that will get us there - and, imo, it's also a way that Google could potentially experiment with selling font IP as a service. I say this largely because it would possibly dovetail with their efforts to sell IP via their recently announced app-store. I don't think many websites display their text solely using images (without use of image replacement techniques) - though maybe I'm wrong? Even non-decent front-end developers have an incentive to use IR; largely because Google's desire to index corresponds with most site owner's desire to be found.