Why do schools enforce a credit limit in summer? / class limit

My school has a bunch of formatting for summer classes and don’t want to get into it. But basically it makes it so you can only take 2 classes in the summer.

Your only allowed 2 6week courses ( even if different summer sessions not even at the same time). And you can take a 3rd if it’s a 3 month class which is all summer. But theirs zero 3 month classes so it doesn’t even apply lol.

I wanted to do 2-2 , 2 classes first summer session and 2 in the later summer sessions.

The first 2 are retakes, and I’ve completed classes at a higher level so they should be relatively easy even if accelerated. The other 2 were future classes.

Just to lighten workload for future semesters. Little harder for those last 2 but again manageable. But I’m not allowed to do that for some reason?

I’m still paying for them, a teacher elects to take summer classes so no teacher is forced to do it. Like what is that problem then?

It’s very annoying , because my future semesters are hard and was really hoping to make it easier for myself I can only rlly handle 15-16 credits at a time not 17-18. (Which is junior spring)