It's not exactly that I'm assuming that, though. I do, however, think that a convergent OS like the one Canonical proposes is a genius idea and people will "buy" it when they see it. If Canonical implements it well (we have yet to see it truly developed, but it looks good so far) they will offer something unique that I think will be easily appealing to consumers and some big hardware names too. (If Canonical's mysterious smartphone hardware partner does desktops as well, you'll see a huge promotion of the concept in a year's time, that's for sure.)
The only reason MS and Apple haven't made a convergent OS is about backwards compatibility. MS has gone as far as shoehorning their mobile paradigm onto the desktop, and mix it horribly with the older paradigm. That's a mess, but they'll keep taking advantage of their position in the desktop and pouring millions in mobile until people either fall for it or send MS to the history books. Apple is betting the house on mobile (mostly tablets), but people still need laptops and they are trying to fulfill the convergence somehow importing things from iOS to OS X. And finally Google, who doesn't give a damn about desktops, is making inroads in that territory with Chromebooks. If they ever get some significant numbers there, you bet Android and Chrome OS will somehow merge.
So yes, I do believe convergence is what people want, even if they don't know yet. I might be wrong, though.
Regarding Steam bashing, I hope you're right. I just see that going your own way in Linux is usually cause of bashing, and God knows Valve is REALLY going solo.