1. Instead of saying my opinion makes no sense, try explaining why you feel that way. Misty got more air time than anyone else, probably as much as Dawn and Iris combined, yet people complain that she still needs to be there. She has had more than enough time, others like Dawn were barely there before getting the boot, that is what is not fair. And killing off a female character to make way for another is often done in more violent shows, hence my point.
2. You are assuming Misty and Ash had a romantic subplot. If anything, they were more like best friends, siblings at most. After over 300 esp, their romance got nowhere and the dynamic was getting stale, hence the change. Misty was one of the reasons why ratings started to tank.
3. Most of the older fans no longer care about Pokemon, which is why they do not know Dawn. If the older fans in the west all saw every ep with Misty and Dawn and were asked which character was better, I would bet the answer would be Dawn. She is way more likable and considerate than Misty, who was just loud and overbearing at times, no offense.
4. How can anyone truly call themselves a Pokemon master without proving it first. She has to compete in a league to prove her worth. Why else has Ash been competing for 16 years if he could just declare himself to be a Pokemon master like Misty has in regards to water Pokemon.