This is more or less what Lewis argues in An Experiment in Criticism. He basically says that we should spend less time arguing about whether a book is good or bad and more time considering what it means to read well, because if a person reads a book well and loves it then that book is good art to that person. The only truly bad book, he argues, is one that cannot be read well, which is a judgement that is almost impossible to make.

What Lewis means by "reading well" took him multiple fairly dense essays to get through, but I suppose it could be summarized as fully receiving, understanding, and appreciating the book as art—it certainly goes beyond mere enjoyment (though, for Lewis, so-called "mere" enjoyment is a crucial part of good literature).

That's what I think schools should be trying to teach: reading well. As you point out, this sub loves to act as if reading is by default superior to other hobbies, when that's clearly not the case. Reading well, though, is something special—not superior to any other form of art appreciation, but arguably "better for you" then other forms of art consumption. (And if people want to simply consume art, that's still fine. But we're specifically talking about education here, and I believe that teachers should be attempting to instill the higher form into their students.)