>>108662887Ignore those other anons for I bring the truth.
Tsundere isn't meant to be constantly flipping back and forth like someone who is bipolar, it meant to start with tsun and evolve into dere. When you look up the proto-archetypes of the character type you find that originally the girl has a reasons to be standoffish or a complete bitch. As the show progress it's meant to be a slow burn until the character even gets to the "love interest" stage, and by then the tsun is supposed to be mostly gone.
The problem comes in two directions. The first is that because of the internet Japan is creatively bankrupt. They still manage good shit, but the vast majority of their works are incredibly derivative. And because anyone can make a derivative the only thing that can make you stand out is shameless pandering. So this creates a feedback loop of shitty writers writing derivatives of derivatives.
The second problem is a cultural one that caused a lot of young men to basically give up on life and fall into anime and video games to pass the time away until they die. So they want relationships and families, but circumstances means they probably won't ever achieve them, so all their anime had simple romances.
So a lot of young boys pick up male adulthood fucking sucks and it's not fucking worth it, so they fall into the "VG and Animes till I die" plan before they even get to the taste of failure. Only these younger guys don't really have experience with girls so they don't know how a relationship is formed. So when it comes time to pander they cut out the "building a relationship part", but keep the cliches of the archetype. So you have characters with no reason to care about the main character (introverts, assholes, people who only talked to him once, etc.) wanting to impale themselves on his dick. I am beginning to ramble, and I am out of room so...
TL;DR; Tsundere is fine. Blame the dickless losers who don't want to have relationships.