I already have a lot of satoshis lost around several bitcoin exchanges. I can't withdraw those satoshis because they don't even worth the fees.
Like me there's thousands of others in the same situation which would make a lot of BTC. So I take it that exchanges keep these satoshis for them.
What do you think? Should exchanges be responsible for the fees and return every satoshi to their owners?
no,exchange have no responsibilty about satoshi left on your account because exchange have own fee,the only one to witdraw your coins is pay that fee,and so far exchange have big fee for witdrawing,just poloniex consistent with small fee,about 0.0001 for bitcoin.