I think that a majority of people feel intuitively that the closer in they get to an opponent, the more dangerous it becomes. And with good reason. The closer in you get, the more tools your opponent has to hit you with.
Many traditional martial arts instructors like the idea of using the more powerful legs from a distance. But this is one dimensional. It's extremely difficult to maintain this distance in a fight.
Don't get me wrong though, some great counter fighters love to play out in that distance. But committed grapplers with good evasive head movement WILL close that gap and move right into the clinch.