It comes down imo to "absolutes"...saying u should always defoliate a lot or not at all imo are equally rigid and counterproductive.
Grow guides have a lot of gorgeous highly defoliated plants and i think newbies can easily fall for the attractive and neat appearance of a defoliated plant.
Its also a lot easier to "do" something than understand why you should or shouldn't. So the guide says defol here and here and its done automatically without consideration.
Then, after doing it, the questions start. They ask...did i take too much? Too little?
And in the end I realized that yes i can and should defol my plants, but only for a REASON. And the reason is not appearance.
The fairest way to say why I should defoliate is because when i grow my plants i wont do a perfect job of training them. So as a result i defol as needed to fix my imperfect grow.
I do not think i can dramatically improve my yield or potency with defoliation of a perfectly grown plant. But i do think i can improve my imperfect veg grow by defoliating judiciously.
From my view telling me i shouldnt makes sense, but doesn't take into account i did not grow it perfectly! Maybe i didnt space out the tops right! Maybe the center got all crowded from my success, but isnt getting the right airflow or light penetration.