Simple question that might have a simple answer. Why isn't Stealth Rock banned? It seems very centralizing and unhealthy for the metagame. Every team carries it and a counter to it. It lowers tons of Pokemon's viability single-handedly, specifically anything weak to Rock (god forbid being 4x weak)
Anyone want to explain this? It kinda turns me off from Smogon.
Don't ban what isn't broken. There is a lot of counterplay to Stealth Rock, be it in the form of hazard removal (Defog or Rapid Spin) or prevention (Taunt or Magic Bounce), which allows for more strategy and playmaking in the game.
Hazards are a necessary evil. They deter mindless switching (and Regenerator healing) and also make it so that Focus Sash should not be spammed but exclusively utilized in the lead role.
Fire-, Ice- and Flying-type Pokémon, some of the biggest victims to Stealth Rock, are strong in their own right considering Fire and Ice are two of the best offensive types in the game and Flying-types are immune to the ubiquitous Earthquake and (Toxic) Spikes (I admit Bug-types are a bit shafted).
Essentially, hazard control is part of the metagame and, while it may seem centralizing or annoying to deal with, adds more to the health of the metagame than it takes away, at least if you ask me.