In contemporary society, some traditions should be discarded simply because they don't make sense. The Indian caste system, fear against homosexuals, an all-male priesthood in the Catholic church and stigmas about circumcision are all cultural traditions that simply need to disappear because the ancient superstitions and reasons to continue these ideals no longer exist. When society grows and evolves, traditions need to change or be dropped because they are no longer necessary.
I don't think that cultural tradition should be discarded in today's society. Cultural tradition helps us to stay together as a culture. And for other cultures it would help us understand other culture. For instance when I first came to USA I didn't know what thanksgiving was, but now I know the importance of why we celebrate thanksgiving and the purpose of it. Same goes for other culture tradition.
A tradition should be evaluated for current need and use against a modem background. If a tradition harms non and is self soothing or self satisfying then it is fine. If it brings more harm then good it needs to be evaluated and either modified or eliminated. Traditions should be just like anything and should be cyclical and evolving. Take Thanksgiving we can probably assume most people don't eat venison, duck, and fish - which was tradition (because it was what was available). And what Thanksgiving stands for is traditionally and fundamentally different depending on if you are Native American or European decent as well. Again it comes down to a living tradition that grows and changes with time.