The hyperbole in this post is ridiculous. Ok, you feel passionate that Tanner should get snaps. But is it really "inexplicable and unfathomable" why the coaches haven't made a move yet? You go on to establish your credentials "I've been doing a lot of thinking about this" and give us "the only logical explanation" and what every other coach in America would do.
Let me give you the real reason why you haven't figured out the right answer here: because you have few to none of the relevant facts and are just a fan. This doesn't mean that the coaching staffs decision is the right one, they could be playing this wrong, but you don't know the reasons, conversations, experiences that are relevant to the decision other than a few that are played out on a public stage.
Too many fans think they know all the answers and that unless the coaches do what they think then they are going to get mad, make up a conspiracy theory, believe it and then get madder. These are usually the ones that are screaming their coaching advice from the stands. My advice is to do less "thinking" about it and enjoy your team.