"What is the difference between someone who takes a course to earn degree credits and someone who takes it for 'personal growth?' Is the course going to be dumbed down for the degree-seeker?"

There are a few issues. First, for a school to be accredited they need to meet certain requirements, many of which are orthogonal to actual learning. Second, it creates a misalignment between what's good for the school and what's good for the students. Third, it tends to create zero-sum dynamics. Fourth, there is the issue of extrinsic motivation undermining intrinsic motivation. And fifth, it attracts students who are extrinsically motivated.

I'm sure it's possible to create a good program that's accredited. But as it currently stands no one has done that yet, at least not at scale, so my default posture is to bet against anyone trying to do it until they can prove that not only do they know their shit, but that they know their shit in regards to psychology/sociology/education specifically.