Earlier quoted context omitted.
A secure global ledger does have value though. At least it does to lots of people.
Yes, Bitcoin seems to be popular in the trade of illegal goods and for paying ransomware. Doesn't exactly explain why most other people invest so much into Bitcoin. And the security is very dubious, considering the track record of Bitcoin exchanges.
try going a step further and ask yourself why is bitcoin "popular in the trade of illegal goods and for paying ransomware".
hint: there's a thing that is even more "popular in the trade of illegal goods and for paying ransomware" - cash.
hopefully it's enough of a nudge in the right direction.