I'm not sure what your experiences of children are but I have three exceptionally clever ones who bring dozens of their peers through my door at one point or another. If there were a pattern there it's that they are in many ways more perceptive than adults about themes and ideas in shows and many programs do cater to that. I'm a fan of Ben and Holly which is extraordinarily subtle in how it conveys complex social themes. My daughter watched it at seven and instantly drew the parallel between the Wise Old Elf and my own union activities, she got the implied racism and class war between the elves and the fairies.
However they are children and you are not, nor is She Ra particularly an attempt to cater to adults attempting to draw faux intellectualisations out of blatant and inconsequential plot holes in painfully weak attempts to impress other adults on an internet forum. On the contrary I'm pretty confident most kids would be fully cognisant of the fact that She Ra was written as a female counterpart or reflection of He Man and that the blazingly obvious hole in the plot was about that parallel rather than being something to question from an in universe perspective.
They wouldn't make a point of drawing attention to that plot hole in a pretentious attempt to find profound insights in the truly mundane because they would assume that much was already a given to any intelligent viewer. The issue isn't one of you seeing kids as having intellectual prowess that most adults don't allow for, but rather you yet again failing to grasp how your ongoing underestimation of everyone makes your attempts to present the most empty and meaningless humdrum observations as being evidence of your own profound insights fall flat. It just looks silly and comes across simultaneously as patronising and embarrassing.
