Officials in my country of origin might lock me out of using banking and government services if I post something wrong on the internet even if I permanently reside abroad, and while I still have relatives there I cannot risk that happening. Oh and if they do and I come back they might also slap me with a 10-20-year sentence for good measure. So nope, can't afford to be any more public than I am (I'm under no illusion that connecting my nickname to my real name isn't a piece of cake, but at least it's one layer of indirection).

I imagine that many people are in very similar boats, and more and more countries steer that way as of late.