That's not totally true. Don Trump had a lot of trouble borrowing money, eventually only Deutsche Bank would deal with him, because they were probably the least ethical bank on Wall Street at the time, and even for them there was a lot of internal controversy about working with him. Yes, ultimately he got the loans and was able to stay in business, but there are other shady operators who didn't and failed, you don't hear as much about them.

Conversely, Warren Buffet famously has a "halo" which means he gets favorable terms because people know that doing business with him will reflect well on them.

Different pockets of finance have different norms about who it's OK to screw and how, and even as an investment professional I don't understand the conventions in areas outside of my specialty. So it's very hard to judge as an outsider what is considered unethical and reputation-destroying, and what is considered aggressive business practices that happen to come at the expense of other sophisticated professionals.