It's just as bad as using magic in a duel.....
Which you get called out on.
Anyway, I like him. I think too many people think he sold his people for the safety of his throne, but I blame those people for being unable to see potential depth in character rather than the character itself for not outwardly expressing their every whim and strategy in a hostile world full of enemies and spies.
Like Alvor says, Nords have never been fair-weather friends. Many of them trust that the Emperor and the Empire knows what they're doing and that this too shall pass, especially when the majority of the higher-ups in the Legion still secretly worship Talos themselves.