The other thing to keep in mind is that if you have a policy of considering 98% to be "close enough", then it only takes 35 of those decisions to remove over half the population. And it'll be exceptionally difficult to work your way back up, because each improvement will be minimal!
(Of course, this assumes that each decision is independent, which, when you're talking about browser support for CSS, is certainly not the case.)
(Of course, this assumes that each decision is independent, which, when you're talking about browser support for CSS, is certainly not the case.)