Basically, I'm saying people can rationally (more or less, considering the person

) assess at least some dangers, and act accordingly. Intimidate is all about distorting that consideration - it's not simply making people afraid, it's using fear to suit one's purposes. Simply appearing dangerous isn't necessarily going to get a badass what he wants - people might be more ready to call for backup, provoke a fight to show off their own toughness, run away, manipulate the character into taking out their enemies, etc. Being Intimidating gives the character more control over how other people act in response to that dangerousness.