Well, to be honest, because I used it a few years ago and went "WHOA" and then ... broke my config and ran away.
I hear it has improved a great deal but I guess it's because in the bad old days you broke things and it broke the config, the control panel was buggy and prior to Thunar the file mananger was a joke (I can't even remember if there was one because I call just using Nautilus).
Still, it's fairly fantastic, I must agree