Honestly, it's not terribly surprising - you're right, we often see the worst, and what exacerbates this further is that its literal decades full of the worst, full of deliberate misreadings of the work in question, but we know the history.
As a point of clarity, I do want to make a distinction here given that this is probably where it gets murky for outsiders (and honestly, even some people participating in it) viewing the debate as it happens. Accepting that Tifa is a love interest is just an agreement on the most basic premise of the LTD with consideration to which of the love interests (Aerith and Tifa) does Cloud love. If, as a shipper, you prefer CA, but as a point of debate you believe that Tifa is endgame, then despite shipping preference, you do land yourself pretty squarely on the CT camp.
But I think that people are still confused by this whole thing and are actually kind of unable to separate the shipping from the discussion because it is true that often shipping bias does colour the discussion; regardless, however, it's never been about discrediting other people's preferences despite it looking like that. I have to say though, a lot of the worst offenders for misunderstanding the situation actually comes from those that like to make the "all these crazy shippers" statement as if shippers are not a major contributor to the fandom and the fan economy.
I used to joke that the only way that people would accept the answer to the debate, despite how clear I think it already is, is if the devs had a press conference to give that answer. We know now that that is not the case at all - a literal interview with the writer and apparently the writer doesn't know their own work?
I think the best the devs can do is to give a clear and definitive answer and walk away. The outcome would be the same in any case: one of the groups will leave the debate happy and satisfied because they won, the other side will probably talk to wall for the conceivable future.