Combination of not wanting to give up under hooks which generally is the more dominant position in the clinch and secondly IMO its got a lot to due with leverage, typically when we see it utilized we also see a substantial difference in height where the added leverage can help make it more effective.
"If you get hit and it hurts hit him back you not knocked out yet."-Joe Doerksen
The Toxic Terrors (FFL)
Georges St. Pierre*Sarra McMann*Pat Curran*Patricio Freire*Uriah Hall
NP FFL Team Toxic Challenge
Fabricio Werdum*Gilbert Melendez*Rick Hawn*John Dodson*Urijah Faber