I have to ask the same question.
Whe I converted to Judaism, I of course started to keep kosher to some degree, not eating pork, shellfish or any other treif animal.
Sometimes I still have to remind the family about it, and at one point my brother made a comment about my refusal to eat pork being prideful on my part.
To tell the truth it completely baffels me why dietary and other behavioral habits are such a problem for those who don’t practice them.
Nobody’s forcing it on any family member, and we’ll even go out of our way to bring our own food, or just eat the vegetables, or whatever it takes to avoid asking the family to cook extra.
But that’s almost as offensive.
It’s completely illogical, and it doesn’t make any sense on any level.