I think what you describe is a necessary part of what I'm trying to get at, but not sufficient enough for it. So, yes, successful products tend to converge, because support and maintenance makes more sense that way. But products are not successful because of this convergence. If there was only one Linux, it would be about as popular as the myriad of them are right now. What it needs to be more popular is to be a product that a giant corporation pushes with all its might. Only that the standard PC market is pretty saturated - which is why a machine like the Valve Deck might be successful for Linux (or already is, if we consider some millions of sold units a success).