Why would we? There is HN, works well, respects our privacy, doesnt abuse its users, so why would be any need for EU alternative?

I fail to see your logic, are you claiming everything American is bad and should be replaced?

As I really dont see it this way, I am using HN but on the other side I will never use Facebook.

And if there would be such an abusive site as Facebook in EU, I wouldnt use it either.