Not true. It helps certain characters, so it does not balance the game, not even in it's base definition. As some said, Marth (on of the top teirs) gets an edge from it.
However, I have seen characters like Link, Luigi, and Ness do well, and even have an edge over others. It maybe confirmation bias (where you look only for things that confirm your belief). There is also a reason a lot of newer players love Roy.