I think something bigger is going on.

Early this year Poloniex was about the get the mainstream exchange and then they started to fuck everything up; not replying anymore, funds that disappeared, verification was taking ages...it looked like they want to get rid of a bunch of customers.

And it looks like bittrex is going the same way. Last week they lowered basic account withdrawal from 4 to 0.4 btc...thats a big decrease...