Kerala's unusual socioeconomic and demographic situation was summarized by author and environmentalist Bill McKibben:[26]

Kerala, a state in India, is a bizarre anomaly among developing nations, a place that offers real hope for the future of the Third World. Though not much larger than Maryland, Kerala has a population as big as California's and a per capita annual income of less than $300. But its infant mortality rate is very low, its literacy rate among the highest on Earth, and its birthrate below America's and falling faster. Kerala's residents live nearly as long as Americans or Europeans. Though mostly a land of paddy-covered plains, statistically Kerala stands out as the Mount Everest of social development; there's truly no place like it.[26]

It's an interesting point. Political activism has been noted before as a plausible contributor to high social capital (especially as traditional social-capital-providing arrangements tend to recede in modern societies), which in turn is a significant contributor to high quality-of-life.

Of course things are not that great if that very same political activism leads to misguided policies which keep you stuck in the middle-income trap, as we see in so many places in South America. But it seems that a legacy of substantial educational achievement (which is lacking elsewhere) has helped Kerala escape that trap.

There are certainly many good things the Communists did, but it has also been the most violent (by democratic standards, not on a North Korea scale). Now, that isn't surprising because that's been the case with communism throughout history. Back then Stalin posters were everywhere, and most of us were only exposed to one side of such people.