IP block owners

Ah, but there isn't an alternative IP block with a driver to pick. As long as nobody making IP blocks supplies drivers, everybody making them gets away with not supplying drivers. Once somebody starts providing competent drivers, everybody else will have to follow suit, as you suggest. But it's hard enough to do and a limited competitive advantage (since everybody else would copy you) that market pressures won't provide the activation energy.

Also, my impression is that you can't do much with an IP block until you fabricate an ASIC that includes it, which is a substantial investment anyway.