Others in the thread have mentioned that the MetaMask wallet provides a warning prior to allowing a site like this to access the wallet.

For reference, this appears to be an example of that warning: https://github.com/MetaMask/metamask-extension/issues/11337

Transcript: "Signing this message can have dangerous side effects. Only sign messages from sites you fully trust with your entire account. This dangerous method will be removed in a future version."

Presumably part of the issue is that a legitimate "NFT mint" transaction might also carry the same warning.