Working in philosophy, I see some move toward this, but it is slow and scattered. The problem is probably partially historical: philosophy PhDs trained in older methods train their students, who become philosophy PhDs trained in their professor's methods+anything that they could weasel into the system which they thought important. (which may not always be good modifications, of course)

It probably doesn't help that your average philosophy grad student starts off by TAing a bunch of courses with a professor who sets up the lecture and the material and the grading standards. Or that a young professor needs to clear classes in an academic structure. It definitely doesn't help that philosophy has a huge bias toward historical works, as you point out.

None of these are excuses, of course. Just factors that slow down innovation in teaching philosophy. (which, of course, slows down the production of better philosophical works)

(2) 20th century philosophers who were way too enamored with cogsci-ignorant armchair philosophy.

This made me chuckle. Truth is often funny.