A UK perspective
Recycling in the UK is also about keeping rubbish out of landfill of which we are running short (and taxed to the hilt by the government). A primary driver of recycling is just keeping down landfill waste instead of being eco-warriors.
Washing at 40 degrees. I don't know about most other countries but in the UK we use biological washing powder. These work best between 3- and 40 degrees. Go much higher and you denature (effectively cook) the enzymes and they can't digest the stains. Therefore these work better at low than high temperatures.