Indigenous peoples are that way for a reason. They want nothing to do with modern culture so it silly to try and impress what "we" as a society feels is best for them. As far as the term "barbarian traditions", that is like the proverbial pot calling the kettle black.
There are places in this world where primitive cultures are still a thing. These people have no idea of how our society functions and they do not care to know. All they know is what they are. Just like wild animals we have no right to try and change people who don't want to be changed. Trying to mess with these kinds of people have never ended pleasantly.
The definition for "barbaric traditions" varies greatly among individuals depending upon their own cultural background and belief system. For this reason, indigenous groups should be allowed to continue practice of traditions that may be viewed as "barbaric" by outsiders. It is unfair to prevent cultural practices due to the subjective views of individuals in positions of authority.
I am torn on this question. I do believe that indigenous cultures should be able to maintain their traditions in most cases. However, there is a big exception in instances of violence or serious harm. For instance, no culture should be allowed to harm helpless children as part of a tradition or ritual.