Don't they read the news? Because if I had bought that amount of coins a decade ago, I'm sure that I'd see out of curiosity how well it has gone. Since the paper wallet was in his closet, it means that he didn't care that much.
People also forget much more important things than if they bought something 9 years ago and paid the same just a few dollars - it's not an investment you think about every night before you go to bed. Since that person offers 0.2 BTC as a reward, it’s probably a max of 2 BTC or maybe less.
There are many examples where some people (much more informed) have lost real wealth because they were careless as is the case with a person who threw an HDD in the trash with a few thousand BTC (and this is not the only such case). One can say whatever one wants, but until 2017 happened people were pretty careless with private keys/seed, and the same thing that is happening now was happening three years ago when many remembered they had something quite valuable.
Specifically, it's not a problem that the paper was in the closet - the problem is that it wasn't protected in a way that someone couldn't just damage it - children and pets don't care too much about the paper, they both destroy it while playing with it.