With that said, the OP's [tgsovlerkhgsel's] general point is still sound, that there is much lower hanging fruit for reducing emissions that would be revealed by a neutral penalty system applied universally, and also show lifestyle changes to be a disproportionately burdensome measure.
It comes down the masses demanding it or not demanding it. You say that personal consumption doesn't make a difference then those who believe you go for the cheaper option even if they can afford the cleaner option. You say that personal efforts can't make a difference then they vote for the party that promises tax reductions instead of the one that promises to enforce fixed gas leaks.
Because the brand of these companies is so valuable, once exposed they actually take steps to fix issues. Perfection is enemy of the good though, but things are actually moving for the better when there is a trend to demand the better.
There's of course counter trends, like eat more meat burn more fuel, screw the foreigners etc. I bet you, if these become dominant, the same brand will be all over it. "For every phone you buy from us, we kill a baby seal and throw a battery in the ocean" could be the next campaign if the ant-environmentalism catches up.
Win-win, isn’t it?
Because they're a company, and the regulatory authorities (EPA & MMS successors) don't have enough funding and will for reliable enforcement.
There are already branches of government tasked with doing this. They just need Congressional support and/or prodding to make it a higher priority.
Especially as a lot of the consumption is indirect - you don't buy the gas, but you buy a meal in a restaurant that was cooked using that gas, or a car whose manufacturer bought the dashboard from a company that bought the plastic from a company that made it using gas from the national gas market, where all gas is fungible and it doesn't matter how it was produced.
Good progress but not enough.
Money well spent I guess.
Some other questions that come to mind:
Who decides what the carbon footprints of everyone's behaviors are?
What level of surveillance is needed to enforce everyone's behaviors?
To what extent will carbon credits markets be subject to regular market events like boom/bust cycles, speculators and other market manipulators?
The difference per 1000 kcal seems to be 5.15 - 1.17 = 3.98 kg. Where do you get 8.8 kg per 250 kcal? Maybe you were looking at the least-efficient beef? 8.8*4 = 35.2 kg per 1000 kcal would match the "beef (beef herd)" value.
Anyway, the idea that personal consumption has no use is absurd. It portrays a false idea that these pipes and factories and what not are made for the personal use of the affluent when in fact all these machinery produce items demanded by the masses. That's why the owners are rich, they produce(facilitate could be a better word) the stuff we want and we give them money to receive the output. Obviously, reducing personal consumption or making choices directly reduces the output of the machinery of the rich.
If you want to blame a class, you are better off blaming private jets, mega yacht and golf courses if you are after the rich. These are the only emissions that are significantly different from the rest.
Then you come to transportation and large homes of the middle class in western countries, especially the USA.