I agree with you completely: legality definitely is not absolute. But if your protest is illegal for no valid or higher moral reason, then I don't think it's worth the risk.

Going back to the "mistakes are good in college" argument, college students should be smart and mature enough to know which mistakes are actually worth the jail time.

College students should be sufficiently smart and mature, yes. I didn't read the article as saying that college students should deliberately make mistakes for the sake of having made them. Rather, the article was focusing more on the response when inadvisable behavior occurs. Should it be seen as a moral fault on the individual, to be punished, or should it be seen as a societal failure, to be used as a teaching moment?

The problem is that it is very hard to have situational rules as a population size gets very large. For a population of 100, everybody knows everybody else, and so any failing can be dealt with on a case-by-case basis. Since you see everybody every day, you can tell which failings are habitual, and which are rare. For a population with limited communication, exile is a useful tool, including self-inflicted exile after social shaming.

This is a useful conversation to have, because we are seeing the first generation with fast communication and indefinite storage. Effectively all college students now have everything about them recorded. 40 years down the line, all politicians will have a searchable history. We, as a society, will need to figure out how to deal with this glut of details, as no previous strategy suits the new situation. There are too many people to keep track of, so one can't get a feel for everybody's habitual behavior. There are also too many details available, so the previous strategy of excluding everybody who has a memorable negative detail available is no longer valid.

This turned into more of a ramble than I had expected, but I think it is a complicated issue, which deserves thought.