There are so many variables in Pokemon, not just deck to deck but event to event and game to game and player to player, and as a lot of people have pointed out, you cannot claim that any one deck is better than another just because of theoretical this or that, or because in isolated instances your deck won over this archetype or that archetype. This is especially true if you play solitairre games, or games against the same handful of people. As has already been suggested, take this to Battle Roads or some other legitimate, balanced, real life tournament. Then, if you're still confident, take it to Cities. Then take it to Regionals. And so on and so forth. Thing is, every game is going to be different, and especially when you start ascending the ranks (if you make it to the top-tier events such as Nationals/Worlds), you are truly going to be playing against people who know this game inside and out, and who know archetypes like Mario inside and out, and who will take all of your preconceived theories about how great your deck is and FORCE you to back them up in the heat of the moment, in person, when it counts. Until then, everything you think you know about the awesomeness of Nidokingler is going to be distorted, speculatory, theoretical, etc..
Also, I think you misunderstand the potency of Mario. It does not have to get a KO on turn 1 to win. That is not mandatory. It just does possess more of an ability to get quick KOs than most decks. Mario may not be all about finesse or intricate combos, but it can have mid-to-late game longevity. Look at its core. Lucario comes out of the gate fast and hard, a 90 HP stage 1 hitting for 40 turn 2 or resistance-evading 30 turn 1. That isn't something to scoff at. He also softens up benched Pokemon at the same time that he's dealing 40 to the active. Again, good stuff. Then you factor in disruption cards like Cessation Crystal and Battle Frontier, and you're hurting a lot of decks, because a lot of decks rely heavily on Powers/Bodies and your deck doesn't. Also factor in Machamp. It has 130 HP and is NOT an Ex, so it doesn't give up two prizes, its first attack does 70 for 1 energy if the opponent got a prize off you last turn, and its second attack does a possible 90 plus confusion for 3. It can "retaliate" for cheap and get you an easy prize, it can clean, it can come out early and give them trouble from the start. For a stage 2, it also has one of the most solid evolution lines out right now. Machop is a real Haymaker of a Pokemon. It is how a lot of first turn KOs happen if they happen at all-- 20 x 2 for 1 energy + 10 from PlusPower/Strength Charm and you've taken down a lot of common Pokemon, including Eevee, Skitty, Holon's Castform, and Pikachu. It also puts a dent in cards like Absol ex. Basically this deck is very solid and does not simply crumble if you can't get some extremely quick KOs in (although the deck is designed to maximize the odds of this). The Pokemon have great HP, they attack for cheap, they do solid/heavy damage, Lucario snipes, Machamp can Confuse, they don't have double weakness, they don't have Powers, their type is one that a lot of Pokemon have weakness to, etc.. You can't just write Mario off so easily, especially not when it is in the hands of a seasoned player.
Also, you should post an in-depth analysis yourself of exactly why you think Nidokingler has an edge over Mario instead of relying on other people to do it. Maybe you have some good points. Maybe you don't. Either way, I think the disclosure of such an analysis would help give some meaning to this thread.