Though there is some benefit to cryptocurrencies that rely on ASICs for mining: it means that someone with a significant amount of CPUs/GPUs under their control (such as botnet operators, or government groups like the NSA) can't waltz in and trivially 51% attack the blockchain with their existing general-purpose hardware, and then go back to using it for other things. An attacker would have to commit to buying/building specialized mining hardware for the attack, and then that hardware can't be repurposed for anything else after the attack other than mining.