Let's just get rid of that idea. It won't happen and also due to the fact that as someone who has played many F2P games..the communities in those games are generally horrid. It is terrible to see a person PK someone over and over again while screaming racial slurs at them.
Because this fanbase for XIV is any better? Take a look around here on this very site. If anything I'd say it's WORSE here then most games... even sonic ones.
The above applies to every MMO and MMORPG in existence. in fact, every single community, both real and digital, has their bad eggs. The more competitive the game/scene, the more primal the bad eggs become (eg. real sports, MOBA's etc).

Having said that, if you honestly believe the FFXIV community (in-game or forum-based) is as bad as you claim, then please don't be offended if I assume that you haven't seen too many gaming communities before making that judgement, though it is not right for either myself (nor yourself) to assume their individual experience here is the same for everyone else, so let's settle on the fact we have conflicting experience on the subject.

Games you described above, such as Black Desert - which is a PvP MMORPG, thus such type of behaviour is actually expected - it is natural to view it as toxic when such play is free to become the norm.

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Now, as to the topic of F2P: Considering SE themselves have vehemently gone against the very notion of F2P, it boggles my mind how these rumours even come about. Last I heard, SE would rather shut the game down entirely instead of reform it into an F2P model. I guess you could say every community also generates its naysayers and doom-sayers.