I would blame the media, who only seem capable of focusing on one issue at a time. Politicians respond to that.
Most environmentalists (like myself) know that we need to change nearly everything we as a species do if we want to avoid a collapse of our civilization. Pick your scenario – economic collapse, 6 degree temperature rise (and counting), sea level rise, resource depletion, peak oil, soil sterility, antibiotic resistant disease, crop failure, pesticides in our foods poisoning us, the obesity epidemic, the fact that we eat fish today that were considered inedible when I was a kid, the lack of fresh water etc etc. There’s plenty more and they’re all very feasible right now.
It is our economic system that delivers all this, supposedly in the name of progress. If we were all happy, perhaps it would be worth it, but most of us aren’t. Why, exactly are we destroying our own habitat in order to make ourselves miserable?
Saying no-one votes for the environment misses the point. The laws of physics, chemistry and biology don’t negotiate. If we have to wait for our “politics is the art of the possible” to reluctantly see the need for action then we’re in deep trouble.
Unfortunately what we need are brave politicians. I don’t see any in the West, so I guess we’re going to have to collapse before we can start to build a sustainable future for humanity. At least that will be better, but it’s going to be interesting getting there.