1. People tried to ring alarm bells about the building codes (and the reactor specifically) not being able to handle earthquakes of a size Fukushima was likely to experience. They were on deaf ears.
2. Japanese government admitted guilt for poor oversight and regulation.
3. Three executives were put on trail for negligence. There were found not guilty, but that's not the same as innocent.
If the question were, say, "how much should we trust the Japanese government?" then Fukushima is not very encouraging. But if it's "how worried should we be about nuclear power?" it seems pretty encouraging to me. Lots of errors and negligence, huge natural disaster, and even so scarcely any lives lost and most of the harm done would have been the same without the nuclear power plant.
Yes, something like 150k people were evacuated because of worries about radiation. What you don't mention is that the total number of people evacuated was 470k. Most of the people who had to leave their homes had to leave not because of anything nuclear but because the enormous tsunami destroyed their homes.
So the Fukushima story is: massive natural disaster that caused enormous destruction and tens of thousands of deaths; a nuclear power plant was in a badly affected area; the damage was expensive to deal with but the total number of resulting deaths was, er, maybe about 1.