No thin-client OS that depends on the web is privacy respecting, as applications run on other people's computers.

I have to trust them as much as the closed source native applications on my computer, and I know which ones I would prefer.

You're confusing privacy with Free software there, Richard.

Is it too late for them to try such a strategy? It seems Google has proven there's a market for this sort of product. Or is Google Docs (etc.) an additional part of the appeal of Chromebooks? I know there's been backlash regarding student usage tracking with ChromeOS; seems like a point of differentiation for Mozilla. It also would seem to have more synergy with improving the desktop Firefox client.

Pretty much that's it. A lot less conflict of interest with a MozillaBook. They're really the only ones who should be doing such a thing at all. I don't think it's too late but Mozilla isn't listening to me. You raise a great point about synergy between development of Firefox and FirefoxOS. The phone and tablet thing is a joke, the world needs and wants FirefoxBooks (they just don't know it yet).