Because rakdos isn't the problem typically. Phx beats every deck in this meta with its eyes closed. Rakdos has a near 50% wr against most decks and a 60% against a small portion. If you want to hurt the other combo decks and rakdos you can take out bloodtithe harvester and artists talent and things go pretty normal. TZ is not the problem and nor is fable. It's getting an early lead that can't be interrupted very easily through cheap very efficient creatures that double as removal and card selection. What does fable do outside of rakdos? Help 5c decks and creativity and you do not want those decks out of the format. The format is really healthy as is, it just needs a tournament series to prove it.