tl/dr - Bitcoin history - digital drug dealing = no Bitcoin as we know it. True or false?
Does it matter?
The porn industry initially caused VHS to win over Betamax, accelerated DVD deployment and was the driving force behind the initial growth of the internet.
Does that mean porn is still the major driving force behind all the information technology in the world? Of course not. It was just first.
Bitcoin solved a transaction & trust problem that is highly important to drug deals, but is useful to anybody else as well.
VISA and banks have tried to make payment systems for legitimate transactions that are barely tolerable, with various fraud protections and chargeback mechanisms etc, but the fact remains is that a payment system that is based on having to trust the payee is inferior and outdated.
So you couldn't trust a drug dealer with a credit card number. Well... turns out you can't trust Target with it either. Bitcoin solves it for both.