How would an alt coin just for shortening addresses be a good thing? Sounds like something no one would ever use, considering firstbits is built right in to Bitcoin - no need to have yet another blockchain taking up space and CPU cycles on your computer. I'll agree with you that it is sad that a shortener like payb.tc is popular though!
Cause just like first bits you would have multiple sites with the blockchain and for the paranoid they would have the blockchain. Not everyone would have the blockchain for this.
Man there's no spamming. But trust is gone and no one will use this again.
It does encourages spamming, read on firstbits works and you will see why. There was no trust in the beginning cause it is based off a decentralized database, we don't need to trust it.