It's so much more pernicious than that. As long as one company controls the One Rendering Engine to Rule Them All, one company de facto controls the Web itself, and everyone else is mostly just along for the ride.
It also - and this is why folks got so keyed up about the last browser monoculture - makes it impossible to create a successful alternative software platform without the support of the One Rendering Engine. So it becomes an agent of an overall software monoculture.
Sadly, I fear that the reason Free Software folks don't seem to be getting quite so keyed up about Chrome is that, at least for now, the One Rendering Engine happens to work on Linux. It seems that even principles can be mercenary.
