According to them, your PS3 isn't owned by you, but by them. Why shell out R3k for something that will never belong to you? Why live in fear of being sued for millions if you so much as turn your system into something you'd like it to do (if that is over and above the purpose you bought it for anyway?)
So perhaps console makers should sell licences to use their hardware just a commercial software publishers do? I think it is reasonable for SONY to withold certain priviledges/features from users who use SONY's hardware for purposes for which it was intended, just as Microsoft does when people make certain modifications to their Xboxen.