Mixed order uses mostly just warscrolls and still get to top8s so it's not that bad. People wouldn't blame GW if they weren't so blatantly pushing old stuff out just to sell more of the new. First compendiums had battalions, named chars and were pretty competitive, so they nerfed them to the ground a year later and now they will introduce Legends and basically say "we are removing this from matched play completely because some people still dare to play it, but as an excuse, you can now buy more of it"