If you really don't like the parent of the child your child is playing with would it be fair to remove your child from the play ground? What would you do if another parent corrects your child or jumps in when you are correcting your child? How do you handle the parents who like to make them selves feel better than you and try to compare your child with their child? I simply ignore them and allow my child to continue playing with theirs. I do how ever find these kinds of parents very irritating though!
it depends on the situation for me. if my child was hurting another child, i would hope another parent would step in if i couldn't get there in time. jumping in when i correct? i ignore. plain and simple. i haven't run into parents trying to feel better by comparing my kids, but i know my kids are unique --- they've only been home for 8 months and are 2 1/2 and 4. i'm proud of how far they've come in that time, so i probably wouldn't even notice!
i would have no problem going to another playground, but if it's just a pain for ME, i would stay there.