I think the starting point has to be a decision on whether attempts to suppress disguised data storage is a cat and mouse game favoring the data embedder or not.

I think it’s fairly obvious that the only way to completely stop arbitrary data embedding is to effectively destroy bitcoin, but unless we agree on this point, we can’t effectively discuss what can and what should be done to make life harder for embedders.

As far as your question, the answer is simple: by not policing the inevitable, we preserve bitcoin as a censorship resistant secure decentralized payment network with digital scarcity. The prior status quo regarding default relay is an eventual mining centralizing force and the rather premature treatment was applied rather swiftly without time for plebs and non-techies to grok the rationale.