if you connect a bank account to withdraw fiat on your account, then yes it matter, you need to provide a non-fake name of course
otherwise if you are there to trade crypto only it does not matter, i would put a fake name, sooner or later trading in fiat with crypto will be obsolete, when bitcoin will take the greater step, i know this, only crypto will be used
Well, I think fiat us not going anywhere anytime soon... you are talking bigger words there.
I think crypto will be huge in the next 5 to 10 years when governments kill cash, but currency issued currencies will still exist, so that means Poloniex will still ask for your name.
The problem is when the governments ask Poloniex about the data of everyone in here. So for example, you have now 0.1 BTC, you deposit it here from your Bitcoin wallet. You buy Ethereum, Maidsafe, Monero or any other good alt, it goes to the moon, you sell for big profit, let's say you bought 0.1 BTC worth of ETH, then you sell during the pump, you make 0.8 BTC, then you say ok, "this is good enough, im not going to risk with more pump and dumps", so you withdraw your 0.8 BTC into your wallet and hold for 5 years. 5 years later Bitcoin is worth 12,000 USD or something like that... then the governments may start asking exchanges because that's a pretty decent amount of money, and the IRS will want to tax that (or whatever you have in your country), so they will know that you once moved 0.8 BTC out of there, and they will ask you where that money is now, and if that name is not the same as yours, you may get into trouble.
I hope this makes sense.