Invest all your life savings into Ripple.

You can be billionaire too

This embraces it. Perfectly depicturing the mutually exclusivity ... opposing redundance.
- I can only invest my life savings for this, or for that. Cannot have both. If I transfer everything into Ripples, other investments have to go.
- Banks allready know a means a electronical money transfer, and Ripple just recently arrived, as the last. Will it replace the formerly employed methods? Really?
Ripple can neither expand, nor replace anything currently in existance. It is not the next killer application.
Ripple might take over because people are tired of miners.
Miners are a bunch of good for nothings that create inflation and suck wealth out of investors.
This argument is more suited for POS, and opposes POW. Exactly my line of argumentation usually.