if you read carefully what I mean behind that expression you would understand. Hashrate is definitively a very vague proxy for total network power. In the end what you want to know is how much mony an adversary would need to attack your network with 5,5kw today you can easily produce 580Thash/s with the upcoming Antminer with an Antminer S9 from the past you would produce 10% of that hashrate with the same electricity it means that overtime, without increasing the dollar amount spent on the network you would have seen a 10X increase in hashrate with people all over twitter claiming that we are doing ATH and that the network is more secure but is just simple math.. the network is secured by electricty/hardrware/infrastructure. Whoever joins now as an adversary will have access to equipment that is very efficient so it's all about the money spent on those elements.. hashrate is a side effect