Funny, that D-Link can just get away with just saying, "Tough sh%t. Go buy a new router".
If any of those routers are under 10 years old, then I would hope that there owners are going to demand that D-Link either replaces them free of charge or gets off its ar$e and fixes the gaping security hole in the router.
Imagine the uproar if a car manufacture came out and said, "Oh yeah we've discovered a failure in the airbags, where they wont actually work, but because the cars involved are more then 5 years old, were not going to do anything about. Buy a new car instead."
It's crazy what firms in the IT world can get away with...