Yeah, a part of it is that there's not really a mechanic class in the way that there used to be. I mentioned that's how my grandpa got his start: He was obsessed with TVs and repaired them/made his own FrankenTVs as a side from his automotive job, which in turn meant that when the computer and arcade revolution hit my dad had the tools and expertise to get really into things like pinball machines, Pong, and Atari leading him to programming which in turn meant I (born in 1988) was raised in a household where pulling apart machines and doing what you want with them (rather than what was taught or what they were 'made' for) was normal.

The decline in basic mechanical tinkering in the population definitely is a factor if only because the mindset transfers to hacking: "This is a human made tool and I am a human with the right/ability to screw with it/alter it to do what I want". Very few kids now grow up being encouraged to play with and take things apart. Both because the adults don't have the knowledge to put it back together or the tools for the kids to use and because our culture is way more risk averse than it used to be.

A lot of products aren't as hackable as they used to be. The obvious comparisons are comparing early laptops to the laptops of today and likewise with old and new smartphones. There are far fewer ports, more soldered on components, and they are harder to even take apart. And there's plenty more electronics where the cost/benefit to figuring out how to repair a product versus just buying a replacement doesn't make sense anymore, but also as you mentioned the mindset isn't as prevalent.

I wish I personally had more opportunity to tinker as a child but I'm glad I have a chance to catch up now, though I'm not really sure where to start. (And I don't have as much time to dedicate since I need to find a full-time job)