Basketball coach isn't most professions. It's a competitive event with binary winners and losers fueled by screaming fans. Tons of adrenaline. Our coach acts like a damn lunatic screaming at neutral arbiters/judges. You think that's okay in most professions? That's a tolerated and sometimes even celebrated activity by a college coach.
This behavior crossed the line, no doubt about it.
5 games is good for a first offense, especially since that's the natural season cut-off. It's a full quarter of the conference season, and 5x more than what the other people who threw punches got. Suspending for the post-season punishes the players a bit when 5 games is enough to send a strong message.