I mean yeah it's easy to blame him for his loss but I want to quote Vitalik Buterin:
"Disappointed at people replying to this with "crypto is what it is, it's your job to be super-careful and write down backup seeds in three places". We can and should create better wallet tech to make security easier."
My issue isn't so much that he lost his bitcoins - like I said, I lost 4 of them once - my issue is that he blames Bitcoin for him losing his BTC.