Seems like a few stories, as well as the crash, have kept people from buying into cryptos. And then the people who made money sold it. Scary thing is, nobody knows.
The entire crypto market is overvalued by any reasonable measure, the question is whether the value catches up to the price -- in which case, the sky's limit -- or whether the price drops to match the value, which is pure potential. Nobody knows.
I'm not sure USDT or Bitfinex specifically make much difference, just the total weight of news and gossip -- of which, USDT and Bitfinex are part of it, along with China, South Korea, bitcoin parodies on US talk shows, etc...