Doing the math is not at issue.
But, saying there are enough crossdressers to fill most nations gives the impression there are more than the actual 2%-5% of the population. I just think it is helpful to put things in context.
I'm not sure why you mentioned the numbers, but if your point was to demonstrate that a high enough number of transgenders will cause the medical/psychiatric community to depathologize the condition and remove it from the DSM, it is not numbers that determine inclusion in the DSM. I dare say there are more people who suffer from depression, anxiety, and ADHD than there are TGs. The continued debate, as Lea stated, is due to there having been a lack of scientific consensus about the nature of transsexuality in the relatively short time since it began to be better understood.
Yes, societies in all cultures (not just Western) need to understand that there are a small number of people whose genders are not congruent with their bodies, and further this is not pathological nor is it a moral weakness. I don't think anyone here will disagree. And I agree that the movement forward to increase awareness to this issue is painfully slow. But, there are members in this forum who have transitioned in place without losing their jobs, which would have been unheard of a generation ago.
I do not foresee a time though, when crossdressers or the gender non-conforming will be embraced in society even if they are tolerated, excepting employers and many spouses. Although I may be wrong, most employers/teachers/students expect to see an individual as either male or female, and they don't understand individuals who wish to switch back and forth or who present a mixture of both gender cues.
Still, in addition to the advocacy groups that continue to push for recognition of sexual and gender diversity, I'd like to see our schools include a more comprehensive instruction in our curriculums. If kids learn at an early age that it's OK to not be cis/hetero-normative, things can only continue to improve in the future ... if we can also remove a religious objection to gender and sexual diversity, in Western culture and worldwide.