My dear sir, it looks like other people are not the only ones 'overreacting' to SwagKey here.
Sorry if I seemed condescending to you, but it is fairly obvious that you either did not ready any of the previous posts or are simply too fixated that SwagKey is the best set. I've already established the shortcomings of the set, mainly its occasional inability to perform even its one job even under perfect circumstances. I don't think the Suicide lead is the most recommended set either (Draining Kiss can't really heal enough to justify the moveslot), as I personally prefer if Klefki didn't die so quickly since it still has a lot it can do, but between its interesting support movepool combined with Prankster, you can't seriously believe that relying solely on luck is the best chance Klefki has in OU. SupportKey does what it can to support the team (which it usually can do); SwagKey flips a coin and hope the opponent doesn't manage to push its face in. If SwagKey has room for Spikes then it would be worth consideration, but pure Swag + T-Wave Klefki is by no means reliable at doing its sole job, hence why it isn't on the main sets.
It's not just that either: what are you doing with SwagKey that other Klefki sets cannot? Spread paralysis? Other Klefkis can just as easily fit Thunder Wave on their sets and stop most sweepers on a mere whim. Sweep teams? Maybe SwagKey can sweep some opponents that do not know how to play around Klefki or are just having a bad day, but other Klefkis can use Spikes to soften up opponents so its teammates that are much more effective at sweeping can do the job much more efficiently.
Yes, I know and have seen replays of SwagKeys taking out entire teams by themselves, but the same can happen if you use Dual Screens Klefki with Spikes alongside 5 sweepers, some of which that can take out bothersome Pokemon like Ground-types, Electric-types, Defoggers / Rapid Spinners, and bulky walls, and they don't have to deal with the luck factor as much as Klefki.
With that said...
It can indeed be a legit strategy, but other Klefkis can bring so much more to the table. Even if SwagKey has the most damage potential out of all the Klefkis, the less offensive versions of Klefki are rarely deadweight if they accomplish their jobs and allow a sweeper / setup sweeper to clean up the opposing team, which they can do with near guaranteed success, unlike SwagKey.