Comp TF2 has two obvious choices, both of which sucks on different levels. The first choice that everyone jumps too is a plugin/script/server magic that removes the nerf. This sucks because all it does is open the divide even further between 6s players, and every other TF2 player on the planet, including HL. It also, on a much lesser scale, opens the gate to change more attributes and further divide 6s away from TF2. You guys might dislike pubbers, but without the general TF2 public, you have no new players, no teams, no one signs up, leagues die (hi ESEA) and the game goes even more stale then it did before. We're on a small upswing (or at least are keeping stable) so that all REALLY sucks.
The second option is to just man up and deal with it. It sucks? Sure does. You can complain to Valve, and its possible (but unlikely) they will hear your calls if numerous enough, but in the event they don't you need to be ready for a shifting meta. The top teams are going to switch things up, more pipe heavy play maybe, more trap heavy....hell maybe with the lack of damage the Demo now shows, perhaps the Loch 'n' Load will be unbanned (lol). You don't know, because this is literally the first day of the patch. Give it time.
There is a third option too; you be a massive drama queen and leave the game 4 evah because a weapon got nerfed. This is obviously stupid, and no one with any mental capacity would actually do this.
In the end, its not the end of days. Maybe a plugin to fix the nerf could end up like Project M for Smash Bros and outshine the original...or it could end like CS Pro Mod and go down in (boring) flames. Either way, TF2 will still be here, there will still be people playing it, and its also just a goddamn video game. Chill, do a conga in pregame and r e l a x. Taking your time is optional.