I guess if you don't trade much you might think that, however in reality I use to buy and sell fiat all the time on BTC-e yet I never deposited or withdrew any. It is a hedge when BTC is crashing like USDT is on Polo, people love the stuff.
I think one of the only reasons the USDT situation is tenable right now is the overall cryptocurrency bubble. When things return to a bear market and everyone wants USD again, things might not look so rosy.
Tether hasn't been able to redeem USDT for USD in 6 months. But as long as everyone is staying in the markets, it doesn't matter. They can move their USDT to one of several exchanges and buy into any number of coins.
This effect will be less apparent on BTC-e, since there is no pretense that is fully backed by the underlying asset (it is a debt obligation, not the asset itself). And even if it were a transferable token (like USDT), I don't think other exchanges would accept it, due to BTC-e's embattled legal situation.