>but the wholesale rejection I hear people making can only come from a place of ignorance.
You went from "complaining about capitalism" to "wholesale rejection of capitalism". We call that shifting-of-goal-posts-ism. :P
Capitalism > productivity > abundance > social welfare
The /it depends/its complicated/its a grey area/ way of thinking is an essential analysis tool, but the average person can't be motivated towards an ideology (political, economic or social) using that. To me, the most progress is made by adopting a zealous attitude at the beginning and then making major course corrections, rather than pissing about with optimizing via micro adjustments from the start. e.g. Give people unfettered capitalism, and then when you get 13 year old kids in coal mines, you give them unfettered welfare/workers comp for a bit, etc. That way both the negative and positive impact from policies is permanently etched in history.