A tie uncomfortable? No way, man! As an almost-daily tie wearer, IMHO ties are only uncomfortable if the are either too tight (usualy a problem of a shirt collar that is too small) or caught in industrial machinery.
The solution for the former problem ... a bigger shirt. The solution for the latter problem ... 'off' button, knife, clip-on, vest ...
Well I think it's more just that it's unnecessary. And whether or not a tie is comfortable, if you do a poll on whether people consider a tie something comfortable to wear, probably 98% are going to say no, and so that's the perception people have of it and so the perception of the tie wearer who doesn't need to wear one is unfortunately going to be "he's being uncomfortable for....?"
It's a little piece of fabric that marks the boundary between formal and trendy casual, and you stand out if you're the only one wearing one.