These stats show that the average LJ user is an 18-year-old girl. I have nothing against 18-year-old girls. But there are certain assumptions about teenaged girls, and what they want, and how to market to them. If you're worried about the potential MySpace-ization of LJ and concerned that Six Apart is ignoring the more mature portion of its userbase, here's what you can do:
1) Go here and specify your full date of birth, including your year of birth. If you don't want everyone to see how old you are, make sure the box that says "show your birthday to other users" is unchecked. The important thing is to get yourself into the database. Do this for any and all LJ accounts you have.
2) Re-post this.
Worth a shot...