I think it's a shame when children/very young people take part in the adult version of reality shows. Martha Collison on GBBO is 17 and doing AS exams. If she doesn't do well then it's a shame she didn't have time to hone her skills a bit, at least until she is an adult. If she does well I don't think she'll have quite the same opportunities to do tv shows, write books etc.
I do feel a bit of a killjoy, but I have seen a quote that bake off made her grow up very fast. Some young people gave that thrust on them such as those bereaved or carers but this is a deliberate decision.
Maybe I'm taking things too far - this us fun and GBBO is relatively gentle as far as these shows go. What do you think?