Gareth Southgate is clearly very good at his job as England manager; we've reached a semifinal and a final! Why is he regarded as such a disaster??

He's been relatively successful, as in, relative to other England managers since 1966. He hasn't won anything but he's come closer and more often than most. The criticism tends to be that he is too negative rather than that he is a disaster. He was a defender though, as a player, so that probably explains why.