Thanks for the thoughtful reply frostfreedet!
I will consider a graphic indicator of my "quality" confidence as primary photos. But, it would be better if I didn't need this workaround.
I'm not as skeptical as you seem to be. I think Ancestry.com has a business reason to care about accuracy. Ultimately, the company makes profits from gaining users and that requires a platform that meets user needs. They also make money from repeat visits to the site and user engagement. If you pull me off this system and on to another because of the accuracy issue, that is a loss to Ancestry.com.
Server load is definitely not an issue if engagement and usage goes up. It is just a cost of success.
That said, the target segment for Ancestry.com is likely different from those using the more robust systems that you suggest. I think the target segment would be the more casual "app" user crowd that wants a simple interface and tool. Because of that Ancestry.com will need to incorporate more "intelligent" features that allow the wisdom of others to easily flow to the casual user. I think "Quality" indicators are a first step... particularly if the "other-tree" hints arrived with some confidence indicator to assist the user in evaluating the quality of these hints.
I'm hoping to push Ancestry.com in the right direction for creating more value to its clients as well as more success for the company. I see quality indicators as the first step of many.