First, gas in the U.S. has been ridiculously cheap for decades. Housing, healthcare, and education costs are utterly teabagged, but gas is cheap, even now at $4. People who whine about gas prices are either (a) typical Boomer Republicans throwing their sense of entitlement around-- you know, the assholes who thought it was okay to go to war over "price gouging" in oil but clapped their fat hands together when their house prices octupled in one generation and young families got robbed (by them)-- or (b) people who live too ungodly far from where they work and are paying far more in lost time than in gas. Commuting (although less so by subway and not at all by bike) is corrosive and it has nothing to do with fuel costs.
Because gas is so cheap, people don't usually think in terms of, "how much gas will I use to get there?" Instead, it's "How far can I drive until I have to fill up?" That's a question that's easier to answer with a miles-per-gallon number.
Still, I agree that it would be better to see the inverse posted. Maybe people would think twice about driving those enormities. Probably not, but one can hope.
Aside from the ad hominem attacks, I think you're factually wrong. The reason people get upset about jumps in gas prices is because it directly affects the bottom line for a majority of Americans, whether they're Republicans or Democrats.
The median family income at the end of 2011 was about $50k. Take home would probably be around $3k/month. If you have a single earner driving 15K miles annually, in a car getting 25mpg, that's going to require 50 gallons of gas a month. So when gas jumps from $3 to $4, that's $50/month of take home pay that vanishes. For a two earner family, $100. Boom, there goes over 3% of take home pay.
For people with incomes below this, the percentage only rises. And they're not likely to have the latest Prius to minimize the impact.
In short, not everyone upset about higher fuel prices is a warmongering, fat-handed asshole who made out like a bandit during the housing bubble.
It's true that gas is cheap, but it's not true that people who whine about gas prices belong to any political or demographic group. It's basically a national past time here. It's like talking about the weather. It's part of our culture and it's something we'd all do at $0.50 / gallon or $5.00 / gallon.
Because gas is so cheap, people don't usually think in terms of, "how much gas will I use to get there?" Instead, it's "How far can I drive until I have to fill up?" That's a question that's easier to answer with a miles-per-gallon number.
Still, I agree that it would be better to see the inverse posted. Maybe people would think twice about driving those enormities. Probably not, but one can hope.