AhEm
A tradition may be dangerous to society because not everybody might agree with it. For example, some cultures might do harmful things or just things that aren't okay in this world that we live in today. "Sacrifices" are still being made in certain cultures and most people just don't like humans and animals being killed for sacrifices. That is just one example that came to mind, and there are many more that can be dangerous to society. This problem of not agreeing on certain traditions that one person has done for years and another that thinks it is horrible is that this could cause fighting, protests, rioting, ect.