It's because they allow companies to pollute at will. It wasn't so much labor costs that soured Business on America. It was America's growing unwillingness to continue allowing Business to privatize all of the profits and social all of the costs of doing business. Environmental safeguards force industry to internalize that aspect of their operations.
This is what China's lax to nonexistent environmental regulations look like on the ground.
Beautiful colors, don't you agree?
Let's dump it here
Care for a drink?
Who needs a rod and reel?
It stinks, doesn't it?