The holy grail

The reason that older people tend to have a problem with existing somewhere in-between the gender binary is due to their rigid programming. In the past the idea of "passing" was absolutely essential if you were to be left alone. This meant that both "crossdressers" and transsexuals aimed for the same thing which was the holy grail if you wanted peace of mind in public. Existing between the two monoliths was a definite no-no and certainly a safety issue.

Today young gender variant and transgender youth don't aim for "passing" (although they may attain it simply through starting hormone treatments early). Their aim is living their truth and being themselves thus much less perturbed by the idea of being singled out. 

Since the public is very aware of them they just confidently exist and don't care what you think of them.