Erica Howton Geni has in fact to standards, one modern 100% based on facts from more recent churchrecords, taxing lengths, military lists, estate records, wills, censuses etc. Either your ancestors are in the records or not, it's that simple and combined with more people taking DNA test, it will improve the lines by detecting the ones that do not fit in due to that an incorrect father has been designated as biological, when he's not. This is a modern standard, it applies only on modern time, or in fact, so long time back in time as the sources are traceable.
The other standard, is for almost everything else before modern time. It depends on what we can find out about the people in question, and how contemporary or reliable that information is regarding to the subject, it's also about finding out if the person was mentioned in different registers or notes, and it may rest on how much it correlates or differs to be considered trustworthy or not when compared, but sometimes it all depends on clues to how they were related, Historians are laying that puzzle, sometimes they agree, sometimes they don't, but it must be plausible, the people in question must fit chronologically, and in some cases it must also make sense in order to be dispayed and set up in our tree.
I believe that Geni can consist of both above, if people valued these simple methods and stuck to the fact over fiction. Marking questionable profiles with for example, "plausible", adding the reasoning behind, it would work. When a branch is considering complete with all what we know, and is as correct as it can be, it should be locked to prevent disturbances, no more mergings, no more profiles added, unless someone raises a discussion and can actually prove otherwise. It's up to every single user to either accept or reject parts in the world tree, but to be able to do that, it must be displayed.