Honestly, I think it's because that is the flag on top of the hill for that brand. They are never innovative or mainstream so what they have is reliability. Which is probably why 90% of them bought a Toyota in the first place. So, they are not just defending Toyota, they're defending their own decision.If you find that weird you haven't spent enough time on Toyota forums Tim lol I've said it a dozen times it's one of the most aggressive owner groups in defending Toyota reliability that I've come across in ownership forums.
But they aren't unique either. I dropped from most owner forums because they become too "culty". They start acting like no one else, especially the manufacturer's own engineers, know anything. Only they know the truth and it cannot go against their core beliefs. They'll defend those choices regardless of whether there is data saying it's false. Mob mentality, ignore the facts go with herd.