And it's surely helping the grant-getting that their researchers have to spend time teaching classes they don't really want to teach. Teaching-focused people, even if you make them full professors, are still comparatively cheap (since they don't need big teams or labs), and I don't think it's obvious that it doesn't make sense, especially if you consider decrease in teaching quality and other factors. And this also happens at institutions that aren't in dire need of cash. (To be clear, I'm not suggesting to do this for all teaching, but if you get good teachers as e.g. postdocs to try and keep them)