It's just that legalism and liberalism both are not the right path to take.
Legalism, as well as Nicolaitianistic antinomianism should both be eschewed.
I am not saying that the Duggars are legalists, either.
It's just that one can stress outward appearance too much. But at the same time, one can put too little on this, and come into the house of God wearing clothing that gets all eyes turning.
My understanding is that the Duggars are big Gothard followers. I don’t know if that’s true, but I have heard that.
I do know that many, many, many people have had to detox from Gothard and it is precisely the point you have made: everything in that system was about appearance (not substance) and the environment was very authoritarian. Obviously not every Gothard person had that experience. But thousands have.
And you are right: both legalism and liberalism are lies. The one is not the corrective to the other. That’s just veering out of one ditch into the other....