>who was just fooling around

In my own professional life, I've found this to be a very divisive statement. For some, it is a sign of wasting time and effort. For others, they use this to describe themselves when they want to do exploration for the goal of finding improvements, without any clear goal because they have a few ideas but none worth putting forward. I've been told to spend time learning AI and have found that saying "Yeah, I'm playing around with it." was the wrong thing to say because it was seen as not doing anything worthwhile. It doesn't matter that I would also say the majority of my tech skills were developed when I was "playing around".

I wonder if this is purely a linguistics breakdown, or if this is tied to some deeper difference in a person's relationship to tech?

Agree it's divisive, and I would argue it speaks more to a person's perception of work vs play more than a relationship to tech. If (the general) you think that play is for children and work is serious biz, then yeah I could see how you wouldn't take someone seriously when they say they're "playing around with it". It's usually not obvious which attitude a person has though without getting to know them a little bit.