I think one reason is because Marvel has done of series of soft reboots over the years. The origins of the Fantastic Four no longer involve the Cold War space race. Reed and Ben are no longer Korean War vets.
By having a soft timeline that malleable to changes in linking fictional characters to real-world events, Marvel has been able to avoid full-scale reboots.
Another reason is that Marvel has controlled the largest slice of the market for the majority of the past three or four decades. When it comes to a money-making venture, there's a certain "If it ain't broke, don't fix it" mentality that would preclude it from doing a line-wide reboot.
I'm guessing this story is going to bridge the gap between the end of Daredevil's current series and the start of a new volume as part of All-New Marvel Now, similar to how Jay & Silent Bob: Chasing Dogma bridged the gap between Jay & Silent Bob's appearances in the Chasing Amy and Dogma films.
Hopefully Marvel will do a $0.99 Daredevil sale on Comixology in conjunction with the launch of Daredevil: Road Warrior. That will definitely give me the impetus to catch up on this excellent series. I have fallen a few issues behind.