This is essentially a discussion of the disposition of what we might call "pre-1500 legacy profiles" on WikiTree. There is no dispute that I know of regarding the creation of new profiles of people who exist only in legend: we don't do it. We all agree on that.
The question as posed relates to the disposition of a profile that was already created before we put pre-1500 restrictions in place. It is a "legacy" profile in that we would not create it today, but it is here, so what do we do with it?
I would guess that a majority of WikiTree's pre-1500 profiles are such legacy profiles; if not a majority, certainly a large number. So if we are going to make policy, we need to make policy for all of the legacy profiles. Otherwise our standard might be, "legends I like can stay, legends I don't must go." Or "legends with advocates can stay, legends without advocates must go." Or "lists of names recorded by Welsh bards can stay because some of the names have panned out, but lists of names in Scandinavian sagas must go because some of them were once worshipped as gods."
I advocate what I consider a "middle way": retain legacy legendary material but identify it as legend, and document the legend. I would like to see a template that creates one of those yellow rectangles that says something like, "This person appears to only exist in legend. See Research Notes for a discussion of origin and impact of the legend." I see genealogy as a subdivision of history, and historical legends were once believed to be true and often their existence influenced later history.
Wikitree avoids actually deleting profiles because WikiTree is a relational database in which every profile is related to other profiles, and deleting profiles compromises the relational system.
But if as a matter of policy we wanted to adopt a purist approach, the simplest way to achieve instant purity would be for the computer overnight to give all pre-1500 profiles (and all profiles with no date) a privacy level of "unlisted". Instantly, all the embarrassing legacy profiles would disappear from visibility on WikiTree or anywhere on the internet, except to their own profile managers. Then pre-1500 certified profile managers who assert that specific profiles meet pre-1500 documentation standards could convert them back to "public". There would of course be various glitches to work out, but that would instantly take the legacy profiles off the table.
But if we're going to take that approach we should do it quickly, because I suspect there is more than one person like me who, when encountering a "garbage" profile, starts with the question "what is this" and tries to figure out what it is and where it came from, and with that approach we have documented some real people and some others that are legendary, but if we're going to take legendary profiles off the table, a lot of that work is wasted. And as long as legacy profiles are left on WikiTree, some of us are going to be curious about them and some of us are going to imagine that improving them is a good thing to do.