Why are someone is going to encrypt the paper wallet?
I think the bigger risk is not that the wallet get stolen instead of forget the passphrase. Or I don´t unterstand the idea behind it?
When securing your coins you have two conflicting issues to address:
1) you want to be able to access the coins at some point in the future
2) you don't want anyone else to be able to access the coins without your permission
If you don't encrypt your paper wallet then you are making (1) more likely, but (2) less likely. If anyone finds your printed paper wallet they can immediately just take your coins.
So you encrypt it. It's relatively hard to crack the password on paper wallets, but there's a risk that you will forget the password yourself. So (1) is less likely, but (2) is more likely.
It's a trade off. Encrypt if you like. Or don't.
