I think it's probably a fair use of server resources so that will be part of the flood control.
Moreover there isn't really a reason you'd do that outside of a test like this or some kind of stuck key, malfunction, etc so it makes sense.
I think a lot of this stuff becomes more server intensive over time because of the stats that are collated over all posts for likes etc. Same reason you can't delete a whole user and posts once they've done 80 posts, or something. The background jobs that crunch numbers will be incremental based on last X seconds or something. If you can delete likes this means other work, maybe?
That said, you can delete posts with impunity so it's unclear.