I have been thinking about this thread and I have concluded Relic is in a tight spot. If they show off ranks (whether skill or time based) they may encourage quitting which nobody wants. If they don't they do not give players who have worked hard the chance to "show off" so to say. I think they have tried to partially fix this by offering paint schemes only at certain ranks (which is really not a great solution because nobody memorizes when they unlock).
the dumbest logic...
why the fuck would people quit if they dont reach X rank? If anything it would make the game way more competitive if you can reach ranks and lose ranks
then you'd probably see more people in tournaments who want to prove themsleves