I've not been a dev for that long, but I've been a dev for 15y or so. For the most part it seems to me like that is an effect of business decisions; workers will learn the skills that get recognized. Which skills those are has changed over time.

I don't see older devs have that quality particularly more then younger devs, what I see is businesses that don't value that type of behavior. And having worked with "wild West cowboy" coders before, the businesses may be right; they often make a real mess things and just rely on other people to clean up after them.

From what I've seen, there are lots of young people who invest in themselves and have passion for the craft, when the business allows them room to grow and doesn't treat them like a code-producing machine.