Continuously adding features repeatedly forks the blockchain. This only makes sense when the user base is tiny. At some point, the features are settled. Also, if features were the only thing determining the success of a coin, Bitcoin would be dead. The only reason DRK may amount to something is because it addresses a fundamental need (anonymity) directly related to the main function (exchange medium). All these coins adding gimmicks aren't going anywhere because a currency just needs to be a currency (again, just look at BTC's dominance).