Actually, we would ban it because it can often remove skill entirely from the game between two players (I am sure there is a better way of saying this but w.e). The issue at the heart of SwagPlay, is firstly that its a fully abusable strategy (so don't bring up other shit like Hydro Pump miss or whatever), and secondly, that it has very little counterplay available. Now, I don't think anyone is claiming SwagPlay is unbeatable, just that in order to beat it you have to open up more (unhealthy) specialisation within your team in order to beat it comfortably. Yes, we can all play stall, and switch around for 300+ turns while we wait for the Swagger mon to PP stall itself out of Swagger, (which sounds really fun and all) but if people are really tossing around Night Shade Reuniclus as the end all counter to SwagPlay, and calling that a solution, then they are kidding themselves. We can all use shitty gimmicks to beat SwagPlay, but lets not forget, if you come up against something that ISN'T SwagPlay, then your gimmick is garbage.
The issue for me, is that SwagPlay can pretty much be used against a battler much more skilled than you, where you rely on your abusable luck in order to get an undeserved win. Apparently, this is the issue thats frustrating some of the higher ranked players, and its something I can see as being frustrating. There is no real slippery slope here if we hammer SwagPlay, so I don't understand why people are bitching about critical hits or whatever, we are just removing something from the metagame that is unhealthy.