I don't think it should take something like climate change to realise we shouldn't be treating the earth like crap. We share this planet with 7 billion other people, and millions of other species. We shouldn't need an excuse like climate change to realise "Hey, maybe pumping millions of ton's of carbon and methane into the air isn't a smart idea". And this doesn't just apply to greenhouse gasses, we should respect our environment in every way, and not pollute it to hell.

I agree that there are way too many variables to make a 'one size fits all' app. However, the issue of different tolerance levels was addressed in the last line of the post: "It also lets you change the 'optimal' and 'sleep' values if you're particularly resistant or weak to caffeine."