Thirdly, Rotom-H is being used as a check towards GeneSun, a common version of the standard Sun team. Sure, Genesect features on the team, but thats not the point, Rotom-H is a simple, "niche" pokemon thats being used to counter random shit. This happens. Just look at Gecs BW1 team that uses fucking Grumpig to check sun teams, or the Lanturn fad a few pages back. These niche pokemon see use in OU somtimes because they are good in the current metagame, and heck, seeing a few niche pokemon in OU I don't see as a bad thing, in fact I think the Dark Horse challenge is encouraging this stuff, but regardless, its just people adapting to the metagame as a whole, I still don't see where you are getting this "Genesect is broken because of Rotom-H seeing more that 1% usage" argument on. Heck, Princess Brii was running Golurk to check Terrakion on his Hail Team, Doom and I ran Claydol on our sun teams to check Terrakion, do we call Terrakion broken too?
Even if this wasn't 100% bullshit, it is 100% irrelevant if you are arguing that genesect should stay in OU. Your argument is basically that Genesect can be checked by random pokemon. So can Kyogre (Shedinja m8). Rotom-h is not good when every team has Tyranitar, SR, Politoed, Heatran, and many teams have not one, but two of these. Simple usage stats tell us that Rotom-h isn't even close to being a niche pokemon in OU, and while you may like him and use him as much as you want, realize that your perspective of Genesect is skewed by the extremes you've taken to not be wrecked by it (make no mistake, running Rotom-h is an extreme measure). The rest of us who don't want to run 3 separate checks to Genesect have had different experiences.