I really don't understand how can anyone think that the Variation system has any affect on the character validity or the overall gameplay of the game. That sounds much more of an excuse to put an extra "reason" to justify one's dislike to the direction of the gameplay or to his claim of a character and/or Variation not being good.
@Gooberking said that very well.
In a more Rushdown based game, even chars that are more Zoning based are gonna be Rushdown-based at least to some extent. That is true for other Rushdown-based MK games like UMK3, and other games from other franchises like MVC and DBFZ. MKX could've no Variations at all and still be a more Rushdown-based game, or vice versa. The same can be said for character validity, how many unbalanced games out there have no Variations or anything like that (and I mean games that are actually unbalanced)? There you go.
Also
@Cursa and
@jcbowie, Reptile's Variation do affect his playstyle. Yes his universal moveset is versatile and giving him the ability to play in a versatile approach, but his Variation-specific moves indicate on how you need to use his versatility. Noxious is the most versatile because it allows you to play both Zoning and Rushdown equally and freely, while Nimble and Deceptive are more Rushdown based, especially Deceptive.
The Variation system is not just about giving each char a vastly distinct gameplan for each char, for some chars it is about changing the approach of the gameplay while keeping the very core of their gameplay the same across all of the Variations. That's another proof that chars in MKX are indeed different then one another.