TV marketing 101

For those genealogists out there who keep lamenting on some genealogy mailing list, message board, or Facebook group that WDYTYA should be using ordinary people instead of celebrities for their subjects, I would put these questions to you:

If you would watch the show regardless of who the subject was, meaning that WDYTYA would get your viewership whether or not they used celebrities, then which do you think would attract more *non*-genealogists to watch the show: celebrities or non-celebrities? And if you rationally respond "celebrities", then why would you expect WDYTYA to act in such a way as to reduce the size of their potential viewing audience?