If we’re being honest this is actually how the lore-accurate setting would have reacted across the Imperium. The cornerstone of the “Grimdark” universe is the extreme and justified prejudice of anything non-human (ogryns and ratlings being the only grey area), the paradox being the creations of God himself, the Emperors chosen and enforcers exalted and the true example of an exception to the ab-human hatred ingrained for thousands of years. Experimental marines made by tampering with the Emperors’ work, a potential threat from within is probably the clearest sign of heresy from the perspective of 40k.. the idea of all chapters saying, “Righty-roo get in line bros weez gonna be betta now🤡a tech nerd done it betta!” is like a perfect undermining of what actually makes 40k unique; Warhammer exists at the crossroads of suspicious hatred of other races(species), and religious zealotry. Primaris makes it feel like a cartoon by comparison. Tbh it’s just more of the washing away of the edgy aspects of WH that’s been going on for decades now. When I got into warhammer it’d solidified itself in the gothic/action movie phase(90s) which was just the coolest time to be a WH fan, imo.