"These chicken feet are so delicious, you want to give it a try?"
Being born in the US, you've never eaten such thing before and you say
"Oh no, that's so disgusting! I can't imagine that you dare eat that..."
How do you think your friend should respond?
There're at least 190 countries in the world, each probably having very unique eating culture. My experience tells me that if you grow up eating something everyday, you just can't feel that it's disgusting, no matter how much it is to people who've not tried it before.
Actually, we don't only have eating culture in this world. We have music, fashion, painting, architecture, to name a few. My love towards Rachimanioff's piano concertos doesn't ridicule your passion on Joan Jett's rock songs. I like Frank Lloyd Wright's architecture doesn't mean that your favoring of Japanese Zen Gardens is bad.
When it comes to a matter of taste, there's just no right or wrong.
If you're arguing for, say, whether a government policy should be approved or not, even if you may hurt some other people's feelings (which isn't necessary in most of the cases methinks), it may be worth it because it has an effect on people's daily lives, some impact on the real world.
If you're arguing against somebody's taste, not only it's invalid because when there's no right or wrong, you just can't argue by definition, the effort is also wasted as it doesn't do any good to the world but hurting others' feelings.
"Well, I'm not arguing. I'm just being honest and expressing my true opinion. Are you telling me that I should lie?"
No, I'm not telling you to lie. But being honest doesn't mean that you need to hurt others' feelings. Even if you're being honest, there are better ways to tell your thoughts.
Taking the chicken feet case as an example, you could instead say
"Oh, that looks interesting. I like eating Shaomai more though, thanks for offering :)"
Hearing that, your friend may not realize that chicken feet are disgusting to you but at least s/he would know that you don't like eating them.
When I was in high school, my Chinese teacher once told us that we shouldn't read Carnegie's book How to Win Friends and Influence People because it would inhibit us from treating people genuinely. I do agree with what he said to a certain degree but I also think that the principles illustrated in the book show some of the most fundamental human traits. One of the principle says that
Show respect for the other person's opinions. Never say, "You're wrong."
If you disagree with other people's taste sharply, they'd think that their feelings are wrong and feel bad, even though that's not your intention.
"As you said, it's not my intention, so it's their problem for interpreting it the wrong way."
Well, using that as an argument is like saying that it's not your intention to kill that guy by pushing him off the building because you think that he'll fly instead of hitting the ground and die.
It's not that people want to interpret your words this way, it's just how human minds work.
It does take some brain power to avoid conveying your message bluntly. However, I think it's worth it. Is that a phony act? I don't think so. Think of it as politeness. Do you think that always saying "thank you" to people after receiving help is phony? Probably not.
Appreciate the difference in tastes among people. It usually is the difference that fosters creativity :)