The fact this question is constantly asked in this day and age is frightening, there is two genders as there is only two sexes, Man and Woman is the biological sex, the science, while male and female is the gender, the language used to describe the biological. Anyone that thinks they are anything other than male or female have an abnormality in the brain or and abnormality in their DNA to cause something different, IE: someone with both genitalia of male and female.
I would say, beliefs that there are more genders than two stems from the want to look and sound special but in reality it just comes off as obnoxious and pointless. I ask everyone just gives up i refuse to use non binary genders because the name its self is an oxymoron and if you want to be called dragon-self i will refuse to speak with you. That is all.
Top down indoctrination. Words have a gender-feminine or masculine. People have a sex, Male or female, Just like other mammals. People also have 10 fingers, 10 toes, Two eyes. No outrage there. Compliance tactics, Shame campaigns are the vehicle of marginalizing and silencing truth and people who disagree in principle, Exercising their first amendment rights, And eventually subjugating and pushing them out of the market as Canada has done who do not adopt their anti-science ideology. There are three stages to this, Much like a jihad, Depending on their status in a culture: stage 1: benign messages like "coexist", "love is love" and emotional appeals. Stage 2 defensive jihad- "words are violence" lawsuits and unconstitutional laws and regulations enacted. Stage 3. Subjugation - convert or be subjugated, No license to work, Fines, Jail.