Why do members leave "About Me" blank?

I came to Similar Worlds from the now defunct Experience Project. I always check people's profile before adding them as a friend. At EP it was customary to describe onself, where one was from, at least the time zone or country. I assumed that everyone will say something about themselves--but I am shocked that on SW only once have I found any information about somebody by clicking on "About Me" -- I don't understand why someone would join this site, which is to communicate with others, without saying something about themselves and why they are here. Otherwise what is the point? Just mindless ranting? So how about doing all of us, and yourself, a favor by telling something about you.