Game of Thrones SE5E10 (Dance with Dragons) spoiler (so really not spoiler at this time any more)
Jon Snow getting murdered is one of my favorite things in the whole Game of Thrones/Song of Ice and Fire story. I think it's a really realistic portrayal of things politics has to deal with and why there's such a term as 'progressiveness'.
It's probably not portrayed in the series enough, but especially in the books it's made very clear that Jon makes a very wise decision letting the Wildlings pass the wall (wise and the only viable option, he feels). However: it's just too much progress for the 'people'. The people being mostly the former scum that is the Night's Watch, though it should be noted here that Alistair Thorne never did anything that he didn't think was the right thing (the actor that plays him, is righty applauded for his performance, btw).
It's a classic tragedy: everyone plays the part he's supposed to be play, circumstances make it so everyone lose. Damn you Gods!