total agree.
in that case that my steem was on Poloniex and i could not move it to steemit was only for a week (i have sold my ETH for an awesome price and bought steem) - i keep all my steem in steemit, not in the exchange - it gives me power and in steemit power is money :)

yes the exchanges are taking advantage of the fact that they are so few and investors don't have to many choices
also this industry is growing a lot in the last times and will grow much more in the future.
I remember in the end of the 90's the yahoo mail would also crash from time to time as it was only the beginning of the email era and also they would multiply users very quickly - until they have reached a number that is not growing so much as in the past and the service is more stable - same will happen with the exchanges going forward in time