You are actually totally wrong, Muay Thai includes a lot of standing clinchwork including throws from the clinch.
Exactly what I've been saying since I joined(Aikiweb). I'd add, Muay-Thai is not grappling, it's strictly a stand up, kick-boxing MA. Also, grappling IS ground. Sorry, so noone gets the wrong idea, I'm not trying to correct as much as 'enlighten'.