I have never used Poloniex but out of the exchanges I have used I've never had a problem. This may be because I haven't been using them long enough.
I think we have to understand how hard it must be to run an exchange and all the work that goes into keeping one running especially with all the hacks that have happened over the years they must spend a lot of time and effort in keeping our money safe before they spend time and effort on anything else.
I hear you but when 10k of bitcoin turns into 6k of bitcoin while they ignore you for a month it stings a bit. It's not easy but when you have millions of dollars in trades going on every day you make some good money and can afford to hire some good staff.