It’s pretty rare to get in-depth feedback in most situations, but there are exceptions. I once had someone tell me my protagonist was annoying, and another person said one of my queer stories was baffling because “the characters are obsessed with their genders.” The one pretty solid exception I see is if it’s a literary agent rejecting a book after they requested a full manuscript from a partial. Even when my books were on submission to PUBLISHERS I often didn’t get much feedback, though that was one place I also did get some pretty decent feedback. But you still see a lot of “unfortunately, we can’t take this” or “thanks, we’re not going to offer at this time” or, very very often, “best of luck placing this elsewhere.” Sometimes they’re hybrid form letters too. But please keep this in perspective: the people you’re most trying to reach are the READERS!
It is really nice to get personal responses from editors (and I’ve had lots of those, at every level), but another good thing to keep in mind is that if you were to be chosen by a publisher, an editor, or an agent, you’d really want most of their attention to go to you/their clients. So the sacrifice they have to make is to cut down on giving in-depth personal feedback or explanations to people they DON’T want to work with. Form letters don’t mean your work sucks, and if your work (or just that piece) does suck, often you won’t find out from the people who read your submissions. Form letters are just a necessary evil.