No actually nodes are ran by many other normal users and bitcoin service providers along with the miners but miners play important role in hard forks. After hard fork the network which will have majority of mining power will survive while the one which doesn't have much support from miners will ultimately die.
Thanks for that... Could we see repeat of Ethereum? Both ETH and ETC are still alive 10 month after the fork with sufficient hash power to support each branch. Ethereum brand has survived so far... I guess ... Nah, we should be fine.