I teach CS at Berkeley, as a lecturer. i.e., I'm contingent and on a contract. And don't really have grant money—though, y'know I actually try to supplement my income so I can live in the Bay Area. I spent years working in EdTech as well.

Others have already say why TA's (and graders) often do the grading. That's also not the same as the prof not paying attention to the work students do.

But I do want folks to think about the time faculty are actually allocated to teach courses. I have a 2 unit course I teach, ~70 students this term, and 2 hours of class. I'm paid for maybe 8 hours per week for all the prep class time, planning. Doesn't actually leave much time at all for grading. There are definitely qualified students who could be TAs who would give the students much more time and feedback than I am able...

For other courses, I have a bit more time allocated, but hundreds of students and still one of me. The only way students get feedback is when TAs grade.

Anyway, that's just the practical bits...

A lot of faculty are moving to 100% proctored assessment, and I think it sucks. For me, reading at least some of the student responses and seeing the data are helpful. Faculty do want to engage with their students and are similarly demoralized when everything is reduced to a transaction. It's hard not to be nihilist about it. Our own jobs, even at a public University are just capitalistic transactions with fewer profits. Students want the degree because it's the only thing they can hold on to as a token of hope for the next few years. Both students and faculty can fall into patterns of really low trust, and it's hard to be the 'outlier' trying to trust students when most of your colleagues say people don't do the work.

I don't actually have great solutions for building intrinsic motivation in students, except talking to them and minimizing the extent to which everything is a transaction. But I'm required to assign grades, still.