Players Like Justin Houston and Weekly Ratings

Justin Houston is an example of a player that’s number 1 after three weeks of play but every weekly projection website I can find has yet to rank him in the top 20. Why does it take so long for a player to prove themselves? Is there something about Houston that I am missing?

OK, as the week progresses a few rankings are moving him up:
Darren Collette Gridiron Experts # 5    
John Norton FootballGuys # 11    
Walton Spurlin FantasySharks # 14


Voted AFC Defensive Player of the Week two times this year.
http://profootballtalk.nbcsports.com/2013/09/25/justin-houston-is-the-afc-defensive-player-of-the-week-for-second-time-this-year/

I can see why he's not a top 10 linebacker ROS in most people's rankings. Aldon Smith had 19 sacks last year and was still basically just a top 15-20 LB in balanced scoring. Hard for those type of linebackers to crack the top 10 (unless you are Von Miller).