Monero developer Riccardo Spagni and stated, “I continue to believe that the vast majority of altcoins are scams. They provide no functionality whatsoever, or the functionality they could provide could very easily be implemented via a sidechain.”
A sidechain is an alternative blockchain to Bitcoin that uses the same Bitcoin currency through a pegging mechanism. The idea is to allow developers to experiment with completely new blockchains without having to bootstrap a new currency network (altcoin). Bitcoin Hivemind and Rootstock are two examples of sidechains currently in development. Blockstream has handled the vast majority of the development work for sidechains up to this point.
Dilley went on to discuss the security concerns associated with altcoins. Critics often point to low network hashrates and alternative consensus models as potential risks of these alternatives to Bitcoin. Dilley added, “If you’re going to fall back to [a weaker security model], you might as well be piggybacking off Bitcoin via sidechains.”
Roger Ver, Bitcoin evangelist and seed investor (Blockchain.info, The Bitcoin Foundation, Ripple, BitPay, ShapeShift, Purse.io)
Peter Todd, Bitcoin core developer, notable skeptic (Coinkite “Chief Naysayer”), inventor of Treechains
Dr. Adam Back, Notable Cypherpunk, inventor of Hashcash Proof-of-Work, Blockstream Co-Founder and President
Andrew Poelstra, author of A Treatise on Altcoins, On Stake and Consensus, co-author of the Sidechains Whitepaper