Yeah, I don't mind yelling at kids when they screw up. A hardass coach is fine by me. And some kids are motivated by yelling generally, so hey, use it if it works.
But physical and mental abuse is a different category than just being a hardass coach. The stuff Wojcik was accused of, for example, crossed a line into emotional abuse. And never should a coach lay a finger on or physically threaten a student athlete.
The stuff about denying water and whatnot... I mean, that would never fly today and for good reason. I know it was common in the 50s and 60s to give a kid a salt pill and send them back out, but it stopped for a reason, much as bloodletting as a medical treatment did. It's not a snowflake thing, it is just a "this is totally counter productive to good conditioning" kind of thing.
I don't know too much about Greg Marshall, but among the allegations were that he punched a player, and choked an assistant coach. If it is credible (and the university at least thought that it was), than that is across the line. And now that that info is public, it would affect recruiting. Who wants to sign up to play for a coach that might punch them if they screw up? He did deny the allegations, but I can understand why he's been radioactive since then.