300 Years of 'Too Big to Jail'

Not really, no. Clinton pardoned a couple of friends, and Bush commuted (but didn't pardon) one of his. George HW Bush pardoned one of Reagan's cronies. As far as I'm aware, Obama isn't accused of pardoning any of his allies (or of them needing any).

Trump did this on a wholesale basis. Many of his close allies were convicted, and he pardoned them. Before him, Presidents interfered very rarely, and it was usually a major event when it did happen. In Trump's case, many were convicted of crimes relating to his getting elected -- not just corruption in office, but fundamentally upsetting the rules of democracy itself.

So while Presidents previously were not always angels, there wasn't an expectation that they'd use the pardon indiscriminately. It's a difference not just of number, but in approach, where the process itself comes into question.