Illegal to hunt them from above, here. But ground blinds work just fine, especially with either acorns or corn nearby.
Illegal to shoot squirrels from a tree stand? What is the purpose of that law?
Sorry for the delay. I've been too busy to waste much time here.
The purpose is to keep squirrel acting like squirrel. Deer didn't used to look up much, then looked higher and higher. It's learned behavior, and ODNR doesn't want it to affect any more game animals.
Other than a bird or two, squirrels don't have natural predator from above, so it is considered unsporting and unethical. Hence, the rule against doing so.