So poloniex takes the fee from the amount someone wants to withdraw too.

Man this brought me in trouble since i asked poloniex to send a certain amount of my bitcoins but what was sent was less. Leading to problems with the receiver.
Why is it that in the bitcoin area there is a habit of taking the fee of the amount to be withdrawn? I mean you ever went to an ATM, asked it to get $100 in cash but instead you got $99 because they took a fee from it

This is annoying and its not only poloniex. When i ask to get a certain amount why does exchanges think i would be happy to receive that amount minus a fee?
Sure, poloniex seems to write that somewhere. But when i ask for a certain amount then i await that amount. If i take too much and no space for fee is left then i would await a warning.
This behaviour of exchanges in bitcoin area is annoying. /Rant end
To make a little more profit with side effects of encouraging people to keep coins with them and discourage using them as a coin mixer plus less transaction lowers resource to run wallet