The thing is that we're talking about celebrities here and, as we all know, these are people who, in real life have gophers (go fors!) to do all their running about ! At the end of the programme they have all their history on a plate - with none of the satisfaction of finding anything out for themselves!
I actually feel sorry for them!( OK! Almost!) Everyone here knows the pleasure of finding that elusive relative after hours/days/weeks of searching, or finding the connection that ties up all the loose ends in a particular family branch. They don't, and probably never will. Our search is the more satisfying for it.
The bottom line is that the show is entertainment, and has set many a person on the journey back through time. The ones with no staying power will fall by the wayside - the ones that are left are in for a history lesson unlike anything they were taught at school and all the more interesting because the people they are reseaching are people they can relate to.
Maybe a voice-over at the end of the show to let viewers know that research is a long, sometimes tedious, drawn out process would help.
Tony