Solosis suffers from being "slower" than Ferroseed/thorn and Escavalier, all of which remain excellent Pokemon due to stat distribution, typing, and movepool. All three of these Pokemon can switch in on most attacks (not sure about HP Fighting on the Ferros), take a hit, and then threaten an OHKO with a powerful Physical move that nothing will like switching into. Don't get me wrong, it seems like it'll be scary, but I don't think it's going to be anywhere near impossible to deal with. This is completely aside from the issue of bringing in a Sucker Punch user and spamming the move until TR runs out.
@Straw Hat Luffy:
Strictly superior stats means having all your stats be higher than the other Pokemon. This is not true in the case of Raticate, as it has higher bulk than Rattata. The obvious issue with doing this via committee is that you run into the problem of people wanting to make their favorites good. "Hey, I think this bad Pokemon is pretty cool, let's give it 200 base Speed and enough defense to take a nuke!" Only conflict lies in that direction. Much better to create a standardized system that has no room for debate. The fact of the matter is, not every Pokemon can be at the same level of power. If they were, then the game would be horrible, because it would be so difficult to reliably prepare for threats. This meta is just a way to mix things up and find some new Pokemon worth exploring that previously couldn't even be touched.