I also could slap anyone who says "I'm proud to be French" or "I'm proud to be American". What exactly are you proud of. Achievements someone else made, who perhaps died hundreds of years ago, who just happened to have the same citizenship as you?
I think it is legitimate to be proud to be
x on the grounds of something that happens now and you contribute to, even through something as simple as paying tax or being publicly employed.
But no, I agree, an inflated sense of pride based on stuff you weren't even alive for is of limited value.
I don't understand the reason for anti-patriotism in Europe. Sure nationalism caused a few problems for you, but turning your back on centuries of tradition and history? You should take a little pride in the nation. Not in 'we're superior to everyone else' sense of course. Just try to see some of the richness of your own history.
You can appreciate and value your history without using it for national self-aggrandising. Look at your history with a critical eye and you'll learn more from it. And tradition is all too often an argument for retaining inequality and injustice.