The previous NCAA testosterone requirement for a male to compete as a female was to bring the testosterone levels down to or below 10 nmol/L. Problem is the normal range for women is .5-2.4 (https://www.healthline.com/health/low-testosterone/testosterone-levels-by-age#normal-testosterone-levels), so the biological male that was born with a biological propensity for larger muscle mass, larger bones, faster muscle movements could compete as a female, despite those previously mentioned advantages AND with still having 4-20 times the testosterone levels as the women he is competing against. How is that fair? Sports have rules for a reason and it is to make it a fair competition.
To your second point, there are very few, if any, sports where women are better than men, so no one cares about a biological woman competing in as a man or even as a woman. Look at the NFL, NBA, MLB, NHL, etc. Do any of them have rules against a woman playing? Not that I know of. But there are none because when you get to that level of competition, you're talking the top .01% of athletes. There are no women in the top .01% for those sports. That's why Serena and Venus Williams, possibly two of the best female tennis players ever, both lost to a man that was ranked 102.
Third, it is not hate. The left is quick to throw out 'hate' because 'hate' is bad and they only have emotional arguments. But, like calling someone racist, if you say it all the time it becomes meaningless. I don't hate these individuals, I feel sorry for them. 40% of transgender people have actively attempted suicide. They have a mental illness and our society has decided that it is better to play into their delusion than help them. If I was walking across a bridge and saw someone about to jump off, would it be hateful of me to tell them they shouldn't? Should I indulge their desire to kill themself and tell them I think they're brave or should I pull them back from the edge and get them help? Which of these actions is loving and which is hateful? These people are actively hurting themselves (and even worse, hurting children) and somehow it is 'hateful' of me to not give them my full support.