I am (temporarily) a prof at such an institution. Most profs in the STEM depts are getting more and more out of date with each passing year. There are no external incentive to learn the latest technical developments. And no time because the teaching load is 5 courses/year unlike 2-3/year at research institutions.

If you are doing research you have to be up to date or you don't get things published. I'm sure there are some professors who don't do research who make it a point of personal pride or something to keep themselves updated, but there's zero pressure to do so.

No, there is tremendous pressure to be up to date with your teaching because if you’re not, then your students don’t get accepted to highly ranked graduate programs, and that is a significant factor in undergrad college rankings.

> If you are doing research you have to be up to date or you don't get things published.

Only within the boundaries of your particular field of study, which in most cases is far narrower than the scope of undergrad classes.

I personally think the truth is somewhere in the middle, but do you see how this explanation is based on a very loose relationship between action and evaluation?