Generating paper wallets in batches means that you are never having to consider compromising on security or best practices because you are in need of a new paper wallet.
Also, if you are going super paranoid and using an old computer and printer which you plan to destroy after creating your paper wallets, it's also much cheaper to create them in batches rather than destroy multiple devices. 
You obviously have to make sure you store your unused paper wallets just as securely as your loaded ones, though.
I would advise against using paper wallets though. It would be better to store your private keys in a USB stick or computer that never touches the internet. When you are ready to spend (some of) your bitcoin, you can sign the transaction offline.
If you are going to import your private key to a wallet on a permanently airgapped computer, then it is no more risky using a paper wallet than using electronic storage. If I'm planning to store a wallet for 10+ years, I don't want to be concerned about hardware degradation or failure which could corrupt my wallet file in that time.