The assumption of the OP, was an “alternate theory” that because their prof didn’t do the work on their end, that it must be the case for all of us. That we’re all lazy, entitled assholes who don’t do the work for our students…
I promise you, I am very average. Plenty of us bend over backwards to do all we can for our students, only to have it thrown in our faces that we don’t do enough.
Many, MANY of us are overworked, since many MANY of us are part-timers with no job security. But we’re still expected to be on top of everything at all times, or we can easily be out of a job and out of academia as failures.