Well, the science is not as clear as you would like it to be. People who have no social experience of the gender they claim to be and yet they insist they are that gender apparently know more about gender than the rest of us. Most of us don’t experience gender as something as specific as transgender people want to make it. We know that society has assigned gender categories and roles and that we are treated according to our perceived gender, whether we like the assumptions and expectations or not—I certainly don’t. All that seems to me like a social construct. Beyond that, people are unique individuals with distinct attributes, tendencies, likes and dislikes. If language is so deficient that it excludes people, then language should be changed, not people.