I think it's more that Linux root stores date from an era when everyone approached CA trust as a binary thing (even browsers), and there has never been enough pressure and coordination to evolve them into a more complex system, unlike browsers. My memory is that browsers added conditional distrust and conditional limits on CAs and various similar things when they became convinced that it would be too bad of a user experience to simply remove CAs but also too dangerous to retain them in fully empowered form. Having conditional distrust also gave browsers more power over CAs, because now browsers had more options for dealing with marginal but (semi-)popular ones.

(I'm the author of the linked-to entry.)