If you're an intrinsically motivated software professional, you're likely motivated by a number of different factors: creating a great product, love of solving problems, writing elegant code, the fun of building new things, making users happy, etc... (exact levels those matter vary by person.) You're probably not intrinsically motivated by things like hitting sprint goals, achieving a certain velocity, meeting OKRs, etc... (Did you enroll in CS classes thinking "I'm so looking forward to hitting sprint targets!"?) Thus, all of these tend to amount to various forms of extrinsic motivation.
A problem with scrum, IMHO, is that it places these extrinsic factors front and center. Yes, the other things may still matter, but the stuff you focus on and talk about week after week are the various scrum related ephemera. (One may include OKRs, which you may not discuss as often but which may represent another extrinsic factor looming in the background.)
There's some evidence to suggest that extrinsic motivation may dampen one's intrinsic motivation, and so a pet theory of mine is that, to the extent scrum does that, it has a certain deflationary effect on the overall morale of an engineering organization. It might be subtle, depending on the particular org and how scrum is implemented[2]. I didn't even notice it until I went to a place that didn't use scrum.
[1] I'm not strongly committed to this idea. It's just something rolling around my brain.
[2] Obviously, some orgs are better than others. I'm open to the idea that the above is more a reflection of "scrum done badly" than scrum itself.