The reason people are not preparing themselves for recessions is that there's not much they can do really. If you look at the average person, they don't hold any massive investments so are not really bothered with the markets' performance. All they can do is hope they won't lose their job.
Another thing is, that the word "recession" is used very loosely. In a situation when even experts can't quite agree on whether we are or aren't in a recession - the recession doesn't seem so scary.
Whatever happens, things are not very likely to get so severe as it was the case in the past, i.e. during the great depression, when people genuinely struggled to feed their families.
I actually don't really agree if there are people who say that recessions are a common thing and often happen repeatedly and can be overcome without any significant impact. But if we look at it as a whole, everyone should be sensitive to such situations and prepare themselves well so that the effects of the recession are not able to hamper the economy to the smallest level.