It being blocked still helps protect them if the card number gets snatched during a transaction. By the time the scammers are ready to use the card numbers, the card would be locked.

Yeah sure, but a keylogger could read it at any time then, while cracking the locally saved card is more complex. And locking the card down unless explicitly needed also means that even if my card card does get compromised, it can't be used of very narrow and random windows, adding a nice layer of security.