Or is the effect opposite - good word, good press, good marketing.
Or, maybe I am completely of track and one has nothing to do with the other?
It's a dry old world if you only focus on access to the material.
But this takes away the barrier of having to actually visit a campus. I think of it as 'freemium' marketing, but for academia.
They are more stingy with grading your exercise questions, because that takes time. But if you are genuinely interested, you can probably find someone to grade your stuff; or if you are advanced enough, just try to write a paper. Professors will probably help you, even if you are not in a university. (Just offer co-authorship, if necessary.)
Students need to be graded. You're paying for assessment as well as education.
There are of course exceptions, i.e, most technology jobs and on the opposite side; medicine.
On the other hand senior professors (not universities, at least to the same degree) trade in fame, not enrollment; Gilbert Strang's career has almost surely only benefited by the fact that we all know his name. MIT probably benefits as well.
However, crappy on-line universities (National, etc) might really be taking a hit from these things -- though, again, one pays for certification not (just) learning.
I think it's an investment in society.