insisted that children are basically good, needing only nurture and encouragement
So you say that conservatives are bad and need to be beaten into submission? (pun intended).
The results were predictable
Well yes, it was understood to be healthier, so it would have positive outcomes. But this was a straw man:
Rules, boundaries, obedience, and discipline were rejected as repressive.
And suggesting this exposes that what you propose is something harsher. Because it's normal and healthy to set rules and discipline, every responsible parent does. It doesn't mean that it should be the army, that children need to be broken, that they should be physically abused, etc.
Marriage was undermined, parents were told to go to their rooms, and the sexual revolution was accelerating. By the early 1970s, groups like the American Psychological Association were normalizing homosexuality and legitimizing sexual perversions as alternative lifestyles
What a slippery slope (but there was progress). This suggests: if you don't beat your kids, they will be perverts and women won't be slaves. But it turns out that your perversity ideal is indeed outdated xenophobic panic and that it's questionable that women should be subjugated. It can also be seen as evidence that the alleged perverts already existed under puritanism, but were bullied and suppressed.
And it's very interesting that the focus is on a particular person, for the general progress of society... Like if it would never happen otherwise. But there are actual valid reasons for it to have happened, it's not just what somebody thought should be the new magic formula of society.
After reading the comment by DarkPhoenix, unless I misunderstood the context, it seems that this actually attempts to whitewash Dobson.