This doesn't sound as bad a situation as you make it out to be...
Dev Person: "Hey boss I finished that X, but I used a framework that hasn't been cool for at least 5 years but it will probably last a decade without a rewrite and everyone can build on top of it."
CEO Person: "That sounds great, please keep doing more of that!"
Admittedly, I like playing with the new shinies as much as the next dev, the above scenario sounds horrible to me to :)
Dev Person: "Hey boss I finished that X, but I used a framework that hasn't been cool for at least 5 years but it will probably last a decade without a rewrite and everyone can build on top of it."
CEO Person: "That sounds great, please keep doing more of that!"
Admittedly, I like playing with the new shinies as much as the next dev, the above scenario sounds horrible to me to :)