Not a single editor supports the rule against articles about non-straight shows, and I sincerely doubt that anyone used children as an argument against LGBTQ+ articles. This rule precedes all active editors and we don't have any more info than any of you.
This is an MDL-wide problem and not an article section-specific problem so I will stay out of the fights and further discussions, but please know that us editors are wholeheartedly on the "please don't discriminate against and please do allow LGBTQ+ content" side.
I, being gay myself, find it painful to enforce the anti-gay article rule and avoid doing so at all cost, something the admins are aware of - and this is why the only answer I will ever give on the subject is to please complain to them directly. I will certainly not try to justify having the rule and/or think of reasons why it may have been created.