There are actually a lot of people at my high school that are into traditional and celtic folk music. One of my friends just joined a traditional vocal group (although they do write some of their own songs) and me and another one of my friends are starting another instrumental (for now) band.
Also, My best friend and I went to a show last night where we were the youngest people except for a couple babies and one teenaged guy, and we had a great time. She's 16 and I'm 17, and we didn't think there was anything "uncool" about going to a place where the average age was probably about 50. This was after we spent the afternoon with my grandparents.
I think that a lot of young people just don't realise how very valuable our elders are and how much we can learn from them. The best thing that all parents and grandparents, etc, can do is try as much as possible to just expose kids to history and tradition as much as possible to make sure that the past lives on.
Peace--Keli