Apologies to be blunt, but I believe the answer falls something along the lines of: "None of your business".
When it's your money, you can wonder about what to do with it. If it's not yours, then what the owner is or isn't doing with it is of no concern to you.
+1
I'm not an OG by any means, but I was up over x60k on my investment in the 2021 bull market and barely sold anything, so I can understand why someone who was up even more decided not to do it.
I know OP might be more interested about people who held bitcoin when it was worth $1, but I know that if we went to $100k somewhere next year, I'd still hold bitcoin.
OP probably comes from a family where owning $100k is a big thing, but not all of us do. Many people live in houses worth 10 or more bitcoin (at current price) and drive cars worth a few coins as well.
The safety that owning an independent asset like bitcoin gives you might be more important to them than some more fiat money in the bank.