Why Don't They Disallow Clinching in Boxing?

I was watching some fights and I noticed that there is incessant clinching being broken up by the referee; especially in the Tyson vs. Holyfield I fight. Why do they even allow clinching in boxing? It's not like MMA where it's actually going to be part of the fight. Why not just make the guys stand up and punch each other; what is the point of allowing this small bit of wrestling?