There are social justice warriors seeking to turn society upside down as an exercise in anarchy, they don't care if they turn out a generation of fucked up kids who don't know what gender they are and can't read or write.
Personally I think a lot of people, especially teenagers - who go through all kinds of phases, are maladjusted and uncomfortable in their own skin and think a change will solve their problems. Plus there's the attention-seeking aspect.
Now we have an industry built up to make money out of them through their 'journey' whether its circular or into a pit of despair - as we've seen with the ritalin generation.
And no I wouldn't want to be black, even if it meant having a marginall larger member.