Posting bail doesn’t mean he paid $175,000. In most cases, those charged with a crime turn to a bail bondsman. Generally, if you are accepted, you pay the bondsman 10% of the bail. So that would be $17,500 if you’re right about the amount. The bondsman puts up the entire amount in exchange for the 10% fee. He keeps the fee and when you are exonerated or convicted, he gets his money back.
If the accused flees the jurisdiction, the bondsman is out the money. Because he doesn’t want to take a loss, he will come after you.
Sometimes bondsman require surety. So, he might say "To pay out X dollars, I want a mortgage on your parents’ home. Of course, parents have to agree. Then if you flee he gets the house.
And, if it’s not obvious, sometimes people borrow from someone else to pay the bail bondsman. So, he or his family may not have actually come up with $17,500 to pay the bondsman.
As others have told you the fact that so many students were cited for drug violations means the college is trying to enforce the rules.