I'm just finishing my 3rd (and final, since I graduate this summer) semester as poetry editor for the online lit journal run by the students in my MFA program. My least favorite duty is to send out the rejection letters.
Ours is a young journal, published twice a year by a new program, but we still get lots of submissions. We choose seven poems to publish from 300-500 that are submitted for each issue, some of them by well-established poets with long lists of publications and awards. So of course we must reject a lot of great writing.
We don't have the option of asking for redrafts, and our staff (all MFA students) changes every year, but we do our best to encourage writers whose work we like with what's called a "tiered rejection" letter that encourages them to send us more of their work in the future. And for the final couple dozen candidates, I personalize the letters a little more, even if it's only to say which of their poems nearly made the final cut. I wish I could offer more specific feedback, but grad students' time is always scarce.
My point is, in trying to read between the lines of a rejection letter, you have to consider what kind of a journal it's from. The points you make here are all beyond dispute as generalizations, but I wouldn't necessarily regard a form letter as a total brush-off.