I disagree with the idea what those who want to disable contactless entirely are paranoid, though I do question the usefulness of a network-side decline as in many of these cases, you would want to fully freeze the card anyway.
In my use case, I’d like to eliminate card clash by only carrying one card that has working contactless (so disabling it at card level, not network level). Of course, for me, my Monzo card would be the primary card so I have to request non-contactless cards from other providers. It’s a pain to have to try and convince somebody that I’m not crazy and that their workarounds are not acceptable.
Contactless cards also have a bad reputation of data leakage thanks to the configurations used by certain issuers and the marketing of products such as NFC blocking sleeves, cards, wallets, etc. Given the huge complexity and secrecy over how it works, I do not blame anybody for entirely opting out of a contactless card or wanting it disabled.