Thank you, Hank!
For most agents/publications, taking the time to respond personally to each piece would be a huge time drain, to the point of making things impossible.
When I started reading for Pam, I told myself that I wouldn’t be one of those people who copy and pasted form letters. So I did individual — if very similar — rejection letters. And I got backlogged almost immediately.
It’s a game of time management. And, keep in mind, for actual agents (i.e., without interns), going through the slush pile is on top of the actual job of representing clients. They just don’t have time to explain.