I agree -- I would totally fly on a plane with uncomfortable seats but an engine that would get me from Tokyo to Seattle 40% faster.

And I am not saying the renderer doesn't matter. My contention is just that the featureset and the UI probably matters more today, for most people. Historically, that wasn't true. (I consider switching from IE "historical". I don't know anybody who uses MSIE today, except for one-off reason like accessing some legacy banking system.)