well, time is one of the biggest costs in any application.
I discussed this same thing with a guy of Digi in their forum. The simple answer of it all is that they are selling AudioSuite plugins, which are non-realtime and they have a great audio quality. So, they are answering the question themselves. If you add that Motu and the others also do it, it's clear that you don't need to bounce in realtime to have the best quality.
Even so, non-realtime bouncing helps for error recovery.