One can argue about whether there is practical use for cryptocurrencies all day long. What you can't argue about is that cryptocurrencies have completely revolutionized trading. In the era of smartphones, twitter, messengers and internet connected toasters it is unreasonable to ask people to stop trading for national holidays, or have the exchange open 9 to 5. People want to trade 24/7, and say what you want, but cryptocurrencies are definitely here to stay if only for this reason.
This is a companion discussion topic for the original entry at http://rados.io/crypto-trading-bots-on-decentralized-exchanges/