actually most dont... SOME of them have it...like 1 in 10 models. and customers go for whats cheap not whats secure 90 percent of the time.
Most do (if not all). You'll find very few that don't have it and those that don't, are probably discontinued products that have been sitting on the shelf for too long. Again, i'm talking about routers aimed at home users, not businesses. As a full time job I sell networking supplies and other computer pheripherals, digital cameras/SLRs, Printers, Monitors, Computers and whatever else comes in your mind. www.microcenter.com will give you a list of items I sell .

Netgear wired routers

NetGear Wireless Routers


Linksys Wired Routers

Linksys Wireless Routers

D-Link Wireless Routers

D-Link Wired Routers

GIGAFAST Wired/Wireless Routers

Belkin Wireless/Wired Routers

Hawking Wireless Routers

Hawking Wired Routers

SMC Wired/Wireless Routers

U.S. Robotics Routers