Many have noted runaway idealism in the young, which in most individuals mature into a more pragmatic recognition of the wisdom of many of our long time institutions. Perhaps, as so often the case, Winston Churchill said it best:
Anyone who was not a liberal at 20 years of age has no heart, while anyone who was still a liberal at 40 has no head.
My insight: Those who remain liberal/progressive at and beyond age 40 are cases of arrested development, a refusal (or inability?) to grow up. In short, some form of mental health difficulty. And for those younger than 40, well they’re just acting their age and, one hopes, with normal maturation will grow out of it.