Riding your kids too hard also causes burnout and rebellion

That's perfectly fine too and encouraging your kids to be not overly ambitious probably leads to a better life for them. However, at that point the parents should also stop demanding better grades from the kid and especially stop asking the teacher to do something about it.

waves I love learning, but I still hate studying with a passion.

Again, that may or may not be an accurate characterisation of the circumstances.

The parent may genuinely be writing at the students request.

It’s seems reasonable there may be at least some students who genuinely want to do more work to improve their chances of being accepted in to their preferred choice at the next level.

When I was in high school (20 odd years ago), the type of student who would want extra credit work was also likely to advocate for themselves quite capably.

I guess it's not impossible that a parent would intercede on behalf of their child, with the child's knowledge and permission, it just seems unlikely to me. Any student who is actually contemplating Princeton is almost by definition extremely self-motivated and independent.

Assuming this child is 15 or older and not developmentally delayed, a parent should absolutely not be intervening for the difference between an A or an A-

This is how you get kids with parents who go to job interviews with them. I actually had to teach a kid I went to undergrad with how to grocery shop because "I never had to do it myself"

Kids need to learn how to be their own advocates.

Why is this something you teach? Even based on common sense alone there is pretty much nothing that you cannot figure out as you go (in regards to grocery shopping).

If it's the parent writing at the student's request… I'd think it'd be more effective if the student themself emailed the teacher about the grade, wouldn't it?

I think the kid themselves have no motivation and what is happening is their parent projecting their dreams and actually ruining their kid's life and future for years to come.

I am assuming kid will struggle in the top school anyways because of parents not being able to control as much anymore and since self-motivation was never trained it will be hard to do things on your own.

You might say that parents will use same approach in top school as well, but if they had that kind of power I guess they would not need to put their kid into a public school in the first place.

It’s pointless to argue over the specifics of someone else’s anecdote. I’m speaking generally.