I can't vouch for why 100% of the booers boo Fedorov, but the guy did manage to build up a decent amount of ill will toward the end of his time in DET.
The thing that does it for me is the sheer number of times the guy used to miss an open net. He'd miss it from 5 feet away and put it wide right or over the crossbar. Maybe he was just snakebitten, maybe he got lazy, I don't know. But that's why I was actually glad to see Fedorov go and why I don't care for him still.
Yes he had some great years in DET. Yes he did things for the team. But he was also a distraction (one big reason why regardless of what Hasek does for the WIngs I'll never care for him), and he seemed to be an offensive liability at times when the WIngs really needed him (which I now find ironic that Datsyuk at his age gets criticized for the same thing).
The smugness, the attiutude, the disappointments... it just all adds up to a lot of WIngs fans hating the guy. And I guess I understand it entirely.
-- Primis.