Heelflips are ugly unless its a variation of some sort. Anybody can make any trick look good, from pressure flips to bennihannas, so I know exceptions exist but the generic heelflip is just plain gross usually.
the only people who hate on varial flips juust learned 360 flips. I can 360 flip big sets of stairs, but couldn't varial flip a 4 to save my life. Different tricks really.