read this to understand why they say don't "reuse" addresses: https://en.bitcoin.it/wiki/Address_reuse

and remember than a paper wallet's main purpose is for you to store some bitcoin away in a safe place. some amount that you don't want to use. for example you buy/receive 1BTC and want to hold it for at least a year, you put that in paper wallet. it is not meant for receiving payments nor for spending from it regularly.