by Turncoat
Why bother with all of that, peer pressure? Is it worth spending money toward that just because others expect you to play along?
I'd keep that candy for myself unless I had something to gain from sharing it. 
If it's not natural/unconditional, no you're right, there is no sense in giving if it doesn't make anyone happy.
Usually there is some way to turn a conflict into an opportunity to get creative and maybe have fun with it.
I even met a couple who had a "divorce" party to celebrate going their separate ways in new directions. Any excuse to have fun with friends, share food and drink, why not?
Why not have a Boycott Christmas party. Or give out "I Hate Christmas" Cards personally printed with a funny msg.
As for what can be gained, by learning to tolerate or share with others, they learn to open up and understand you. So both people can gain by stretching half way to meet in the middle. Only where it comes natural, never forced.