It's not a matter of being afraid to look for better options, either. It's about being disheartened and pissed off that those alternate options never work, so you say "Fuck this." and make a Sandstorm team or whatever the new meta is.
I play shitloads of video games. Most of the modern ones have some degree of creative flexibility in them. Different movesets and items in Pokemon. Different loadouts in Team Fortress 2. Nearly infinite different ways to build robots in Robocraft, or spaceships in Kerbal Space Program. And what I've found is that Sturgeon's Revelation (AKA, "90% of everything is crap.") is just as prevalent in video games as it is everywhere else. Your combination and methods may seem new and quirky and fun on paper... Then you take it out to the field and it gets violently sodomized in almost every situation.
Besides, I don't mean to sound rude, but your feats ITT aren't exactly original or groundbreaking. Infernape and especially Greninja are two of the strongest and most-used Pokemon in the games. Furthermore, Mach Punch Iron Fist Infernape is
already one of its most popular incarnations. And with much stronger items, no less: Your +10% Black Belt bonus has only WEAKENED it compared to +30% Life Orb and +50% Choice Band. Hell, even Muscle Band is a better choice than Black Belt: At least that gives a (slight) power increase to ALL of the physical moves your Infernape will no doubt be using as opposed to just the Fighting-type ones.
Lastly, you're only mentioning sole instances of your success (again, with very strong Pokemon: I'd be more impressed if, for instance, you Iron Fist-fucked multiple enemies with Hitmonchan instead of Infernape, or you super-Ice Beamed half of your opponent's team to death with Omastar or Sharknado). What sort of win-loss ratio do you have? And with what kind of team? Competitive Serious Shit Pokemon isn't like the anime, or even the in-game games. You need a team that all six of your Pokemon fit into well. I'm assuming that Greninja and Infernape are your sweepers. Who is supporting them and how? How well does the team as a whole work? You need to consider all of that before you can say that you have a creative, new, winning strategy.