Looks like I can bring a different perspective to this discussion. I've been mostly using semistall and U-turn Lando is just utterly broken against any defensively leaning team. Life Orb Hydreigon, it can outpredict the crap out of you and you can still limit it to one kill each time it comes in just by letting it Draco Meteor, which then allows you to set up hazards or with an offensive mon. Against Landorus, you can't do that; you have two choices. You sacrifice whatever it just came in on, allowing you to bring in...what? Nothing which beats Landorus on a defensive build can do anything useful for the team; you just scare it out and let the opponent bring a different offensive threat (or Tar, depending on your Pokémon). You've lost a crucial Pokémon, for nothing. Alternatively, you can switch to a counter. Latias / Celebi get U-turned on and die. SpDef Zapdos get's U-turned on and has to take the probable Sandstorm + Stealth Rock damage. Blissey, SpDef Jelli etc, are still Pursuit weak, and even without that, U-turn + SR + Sandstorm puts them quickly into Earth Power 2HKO range. Really the only way I've found to reliably beat it is to use Politoed + Tentacruel + Zapdos / Togekiss, which is just stupid.
Basically, you cannot even check Landorus' destruction unless a) most of your team is faster than it, thus giving it very few opportunities to come in, or b) your team doesn't care about losing a Pokémon. In other words, you can't use anything other than offense. I know this argument has been hashed and re-hashed a thousand times, but because U-turn Lando isn't broken in our current Lando-dominated metagame, in which virtually every team style weak to Lando has been killed off, doesn't mean it isn't ban worthy at all.