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?
The exchanges haven't kept your satoshis. They're waiting for you to add more and then you can withdraw them. It's the protocol's fault that it costs so much to move them.