I don't agree with this part. Based on Vasiliev's History of the Byzantine Empire, 324–1453, which is one of the most reputable history books on the Byzantine empire, there was a popular emergence of Greek identity as opposed to Roman in the later empire.
"In the epoch of the Palaeologi one may note the interesting fact of the rise of patriotism among the Greek people, accompanied by a turning back to the glories of ancient Greece. For instance, officially the emperors continued to bear the usual title of basileus and autocrat of the Romans, but some prominent men of the time tried to persuade the basileus to take the new title Emperor of the Hellenes"
“some prominent men” does not sound very “popular” to me, sounds more like elitist. And I believe it has already been established that the elites turned more towards their Greek past in the late empire akin to how Latin elites were turning towards their Roman past with the renaissance. I believe that common people were much less affected by both of these movements.
There is a lot of complexity and nuance here, and you need to be careful not to misinterpret it. They weren't necessarily striving to become Greek, or a Greek people. They didn't really have that Greek identity or nationalism until much later on, especially under Ottoman rule. Maybe we can find moments or pockets here and there, but there really wasn't much of that going on, they were thoroughly Romanised and very proud of it. What they did have was a resurgence of Greek culture and history. So yes, a harkening back to the accomplishments of Alexander and to the Odyssey etc. But this wasn't at the expense of being Roman, it was more like adding icing to the cake.
You need consider their duality. People can hold two things as true. They were Romans, with the legacy of Rome, Roman laws, Roman rule, Roman military might and engineering, and could count Rome's accomplishments as their own. But they also spoke a Greek language, and lived on Greek land, and had Greek ancestors, and had Greek education and Greek stories, and could count Alexander's accomplishments as their own. There was a growing desire over time to recognise that Greek history as their history, not just the Roman history, and to delve into all the Greek mythos etc. But this wasn't a Greek nationalism or separatism, those are more modern ideas. Also, that theme, of being enamoured with the Greek stories etc, it's a constant throughout all of the Roman Empire's history too, the Philhellenes. But this of course was going to accelerate when they lost much of the territory that spoke other languages, not just Latin but Coptic too. Losing Egypt accelerated that Greek resurgence, because what was left was Greek speakers on Greek land, in the last remnant of the Roman Empire.
Then of course, we are also generalising a large group of people over a 1,000 year period, or even close to 1,600 years if you count the first moment Rome conquered Greece. It's a long period of time with a great number of people. Their identity, language, culture etc all evolved constantly, and people often had different views. For example there was at one point the idea that Greek was pagan with pagan ideas, and that the history and stories should be forgotten, and Latin favoured.
I agree with what you are saying, but it's not weird to draw a line between Greek and Latin because that line exists and will always exist
They are different languages with different alphabets and different laws that govern them, you can however argue that the Easter part of the Roman Empire changed it's court language from Latin to Greek, and even assimilated that greek into a new idendity, but that doesn't dissolve the difference between the languages
Also please keep in mind that the response was given to the concept of the City of Rome change in language being similair to that of the Easter Roman Empire, which i disagree with for the reasons i gave
Oh they are quite distinct for sure, Greek and Latin having split from Proto Indo European around 5,000 years ago, whereas Italian diverged from Latin around 1,500 years ago. So I agree that it's not a direct parallel, since one was an evolution of the existing language and the other was picking favourites between two existing more distantly related languages.
We make this mistake of wanting to categorise things based on very neat and clear criteria. So that would be the Roman Empire was Latin. Nice, simple, clear. But it's not true. The Republic certainly started as a Latin construct. But they chose to expand across Europe and grant Roman citizenship to large swathes of it, people speaking all kinds of languages. Much of the elite chose to speak Greek and favoured Greek over Latin more as time went on. Greek was always seen as a more prestigious language, one of refinement and culture, a language of the elite. It was elitism and snobbery that led to them favouring Greek basically. Latin was the language of the masses, politics and legal affairs. Greek was the language of culture, education etc. Rome was very much a multilingual state.
But I digress. It was all still the same empire, they just shifted culturally. Greek didn't even become the court language until around 620 in Eastern Rome / Byzantium. Until then they were still speaking Latin and writing in Latin for all state affairs. Because it was just a continuation of Roman rule. When they did finally shift over to Greek it made practical sense to do so, since they didn't really have many Latin speakers left, having lost the west, and Greek being such a prestigious language. They translated existing Roman law and records into Greek and carried on, as Romans who spoke Romaica, the Greek language which had developed under Roman rule.
Just a fun little tidbit I will note. The main reason Latin even spread through the empire in the west is that much of the west spoke Celtic languages which were very closely related to Latin, so it was a very easy swap for the Celts to make. Celtic and Latin were so closely related that often they could understand each other. Add to this that Latin was the prestige language, and the language of the ruling class, power etc, and it was a given that they would shift. But the East had Greek, which was an even more prestigious language than Latin, so Latin existed in the East in a complementary fashion, being the language of laws, the state etc, but never replacing Greek.