[evol262]

That's also true of the areas in Southern Italy, Sicily, North Africa, and Illyria. Nothing about the East differentiated it, and the Romans saying that it conquered them culturally were the same as the Americans now lamenting that the US has seen cultural changes. "Oh no! You're not sending consular armies out every year to acquire new territory as your sole cultural identity!" was the complaint.

Completing the conquest of the Mediterranean basin and being left bordering only states against whom the Romans never had any particular success, the Sahara, (Parthians/Sassanids) or holding the line against rotating groups of peoples pushed further west in the Balkans and Germania left the Roman state without obvious paths to expansion. That does not mean that Hellenistic states "conquered them culturally".

If you think the West was some unified area with "Latin-speaking" culture, heritage, bureaucracy, and self-identity, you'd need to write a thesis-length paper justifying it no matter what century. Even the Italian peninsula was none of those things until long after the establishment of the Principate, at which point wealth had already precluded the existence of men like Cincinnatus.