I think the impact of tether on the price is vastly overrated. Let's say tether is being used for fractional reserve-like practices. So what? We are dealing with the dollar all the time. BTC/USD is also compared against a fractional reserve currency. You can't stop these practices. Tether is a tiny amount of the money pot in bitcoin anyway. People comparing an hypothetical tether crash with Mt Gox 2.0 are out of their mind.
All markets have leaders and when it comes to USD that's been Bitfinex for a long, long time. It doesn't matter if all of the rest of the market is real dollars and BFX is fake, the market will follow BFX for whatever reason and those fake dollars will drag the real ones along with them regardless of the proportion that BFX constitutes.
That means it does matter.
I've no idea what the score is with Tether, but to regard it as irrelevant is not the sensible thing to do.