The difference is the mugger gets your wallet one way or the other. The only difference is if you survive to tell the story. The ransomware attacker is only rewarded if the victim capitulates.

Edit: On the other hand, if the counter-factual was a mugger at an ATM demanding you enter your PIN, that distinction doesn't exist. So maybe you're right.

Maybe the right answer is to outlaw paying the ransom except to save human life, but also create a federal fund to compensate victims of these attacks.