This is one of the most obnoxious posts I've seen on here for a while. At 4-0 the Feyenoord fans could still be heard, and as someone who works in an office full of Feyenoord fans, they have had nothing but praise for us today. One of them even said he'll be watching more City games from now on because we played some of the best football he's ever seen.
I see no reason for you to act like that toward their fans, they were welcoming and they created a fantastic atmosphere. There are also worse grounds in the premier league, and that's where all the money is. As far as Dutch grounds go, this is one of the better ones. Not all national leagues are as fortunate as we are.