Not sure I understand how someone can promote/build electric cars for their ‘green’ benefits and then burn all that fuel for no reason.
Well for one it's an infinitesimally small contribution to our emissions while working on something that is very important in the grand scheme.
And secondly there is no other way to do it, you can burn Hydrogen and Oxygen but you can't produce that on Mars so Methane is the only option.
I'm sure if and when we need to leave the planet the technology will be there rather then just blowing stuff up all the time trying to get nowhere. Maybe if they want to ban internal combustion engines in 20xx they should be rebuild the power network and be constructing coal fired power stations instead!!