>>96483087
BL works when you take it as loyalist misinformation and propaganda, anon. The CF fought for decades to rebuild their strength, and they did so with every game /Your Dudes/ played.
Guilliman adjudicated himself their victory to cement his claim for the throne, and is muzzling the chapter by giving them a "gift of strength" (and foreign influence) they can ill afford to ignore.
Do remember the Ultramarine's motto was "OUR PRESENCE REMAKES THE PAST"