Not very ethical, but rational, profitable, and prevalent. Cost is a large area to compete in, and people are expensive.
It would be nice if companies acted ethically, but that isn't their reason for existence (especially in fast growing or large companies). If it's not surprising to me when companies act unethically, can I honestly say that I expect them to act ethically? Not if expect means "assign high probability to".
I agree that regulation is needed. It seems that often basic economics (people want to move around as cheaply as possible) lead to unethical situations (paying people as little as possible to move people around). I'm far from an expert of economics, but it seems like regulation is a way to change the rules of the game to have more ethical/fair/uniformly distributed equilibriums at some cost in net efficiency.