I agree that more could have been shown but I also view this show more as a way to entertain and entice people to check out Ancestry.com.
I do feel sometimes that people walk away with the feeling that a few clicks here and there and they'll find all they need.
The time constraints also leave little room to show the work put into researching. In the end it's a tv show competing for ratings--IMO. Because of that they went for a mass appeal. If it really went into detail of all involved that would definitely appeal to researchers but not necessarily those just watching for the celebrity aspect which is probably a much greater number than researchers.
Of course that's just me guessing and I would love to see a show where they take a person celebrity or not and start from the very beginning step by step. In fact they can go grab one of those people who call me and say "Do you have any books written about my family?" They would be good examples.