Nothing is wrong with adding any gameplay element, skill-based or
otherwise, if the players feel it enhances the game.
But the subject of this thread does not advertise a skill-based gameplay
element, it advertises a method for achieving game balance. Those are
completely different things! If I'm acting as a game designer, I don't want a technique I use for balancing my game to change the nature of that game or alter the skills required to win.