These statements are incorrect. Implying that we should "get better" at team-building is a terrible excuse to imply that Genesect is a balancing factor. A balance factor is what it is, balanced. Forcing people to switch into using Heatran, Rotom-H, or using Genesect itself is not balancing the meta, it's over centralizing it. Speaking of using Genesect, having to using Genesect to counter it itself is absolutely crap. The ideology of "If it's overpowered, then you yourself have to use it" is not a good excuse, in fact it's doing the opposite effect on most people. Also, define beat because there is not many pokemon that can "beat" Genesect. You can revenge kill it sure but, there is an extremely small handful of pokemon that can "beat" Genesect. Genesect's game is highly dependent on the player and 9/10, Genesect excels at whatever task it's given. How are we supposed to know that Genesect was going to kill my Garchomp so his Garchomp or Charizard-X can setup and sweep?
Also, unpredictability is the exact reason why Genesect is getting banned in the first place. There are many variables like you said that Genesect has the ability to use. We have to think hard on what set of Genesect you could be running. What if you are running Iron Head instead of Flamethrower, Ice Beam instead of Bug Buzz, Explosion instead of U-Turn? Unpredictability can differ between pokemon to pokemon. Gengar is a good exmaple as Gengar can run multiple sets effectively. The difference between that and Genesect is that it can't be thrown on most teams to fit most purposes, has more glaring weaknesses compared Genesect, and has much more Checks and Counters to it. If Gengar was a problem, we would have thrown it in the Tier Discussion list.
That statement in itself is false. Genesect doesn't promote originality, it only promotes originality in itself. What has Genesect done to the meta that forces people to run other set? Genesect has forced Stall to disappear, promoted more Hyper Offensive play, and killed off potential for other Leads like Greninja, Terrakion, or Anti-Meta Aegislash.
Those do exist as decent Checks and Counters towards Genesect but the problem is, when is that ever going to happen? If you are a smart Genesect user, you wouldn't let your Genesect die so early and switch it out towards something that automatically threatens said Checks. Like you said, if you are smart team-builder this thing wouldn't happen to Genesect and you would still win regardless.
I'm not here trying to be the bad guy. i'm just pointing out facts.