Make a clone and change the mining algorithm...oh wait...lol

Ripple had most opposition among current bitcoin holders. If somebody would make a clone, where ripple ledger would be created by importing latest bitcoin ledger as genesis "block" (no history, just address-balance), all bitcoin holders would automatically become ripple-clone stakeholders. Additionally, exchanges with shared wallets would have a great incentive to become gateways, which are a critical part of ripple infrastructure.