The other people have paid for their campsite just like you did. They have the same right to be on the campsite that you do. If there is no where else to move to, you have 2 options. One, just accept the baby crying, or two: Leave and go home.
It's not fair to demand they leave. It's not like you're in a public library or church or something?
We are currently at a campground and have butt-heads for neighbors. I wish they'd disappear! Yea, it's crappy! I've even talked to the people in the park office, and nothing has happened.
I now have 2 choices: Accept the idiot's behavior or leave myself. I've chosen to ignore him the best I can and get lost in my own world and to H*** with him!
Noises are awful, but that's the risk we take when we go to a park where there's someone else there beside you (or me). I'm becoming an old fart now, and my tolerance level is getting less and less. I constantly have to remind myself, I once walked in those same shoes. MY KIDS DID THEIR SHARE of crying when they were little and we were camping! I also did some pretty inconsiderate, obnoxious, and stupid things camping in my younger years too, that I'm sure some old fart wanted to stick a hot fire poker right up my south side!
So, live and let live! We've all been there, done that, and even been the "cause" of discomfort for others also.