I think it's horses for courses - if you find this sort of thing irritating, then don't watch.
However, I think dealing with history, taking us back to different times and showing how people (whether famous or not) are affected by finding out how their ancestors lived (which is something which has happened to all of us, here, am I right?) is very interesting.
It's not a programme about how to do genealogical research, in my view, it's a programme about discovering things and then seeing the effects of family history on a particular person.
And having been first of all intrigued, then hooked, then fascinated and then, honestly, totally affected in my day to day life by my own genealogical researches, I find it very interesting to watch.
Thanks to Archivos for explaining how it's set up. If you've been involved in previous Who Do You Think You Are programmes, Archivos, (it sounds as if you may have been) then thank you. They're always on my "must watch" list.