what we refer to (and what you're thinking of) as "the byzantine empire" only controlled the middle east for about 200 years after the fall of rome and the western empire. after the rise of islam it controlled a large portion of the balkans and greece, and parts of asia minor and anatolia, but almost nothing outside of that besides antioch and the bottom part of the boot of italy. it spent the rest of its days fighting the sultanate of rum, crusaders, and turks.
take a look at this and tell us again how the empire stayed "more or less intact for over 1000 years":
constantinople itself was sacked by crusaders in 1204 and not retaken by the byzantines for another 50 years. at that point the city was no longer a centre of culture and education and learning, it was drastically depopulated and barely able to defend itself for the next 200 years despite being the single most strategically defensible location on earth.
constantinople was indeed a highly cultured, educated, scientific city for a few hundred years after the fall of western rome. nobody's denying that. the architectural accomplishments in particular of the eastern empire are nothing short of spectacular in the days when the largest thing built west of constantinople between around 450-1000 was this royal tomb:
nor am i trying to say that the byzantine world contributed nothing to the renaissance either. that would be equally stupid. when the crusaders sacked the city many of the documents in the university were taken off to western europe, even though the vast majority were lost when the university was burned to the ground (there's western europe showing off that "philosophical DNA" you seem to think is inherent).
but what is bugging me most about this is your instant rejection of the islamic sciences being the major force in advancing knowledge in the middle ages, as if even the notion is offensive.
the "house of wisdom" was founded by the abbasid caliph in baghdad in the late 700s. he invited scholars from all over the world to come and study there, and hired huge teams of scribes and translators to copy any written material that could be gathered from all corners of the caliphate into arabic. these included greek texts, chinese texts, indian texts, african texts, and very often these translations are the only surviving copy of the original documents that we still have today. these documents were about every scholarly subject you can think of, from alchemy to medicine to mathematics to architecture. they invented calendars, weights and measures, and methods for keeping time and making measurements that we still use today. they invented the number system we use (we still call them "arabic numerals"). they invented the very concept of "zero". without the
islamic caliph founding the house of wisdom, there would quite literally be *enormous* gaps in human knowledge that we would either simply not know about anymore or would have had to rediscover from scratch. that's a fact.
wisdom and knowledge were so highly prized by the caliphate that peace treaties after wars won by the caliphate frequently claimed books and scrolls as the victor's spoils of war rather than the usual gold and grain plunder.
the caliph himself made frequent trips to cairo to sponsor and personally take part in the first archaeological excavations of the great pyramids of giza. the west would not begin to approach archaeology in a scientific way for many centuries.
take a look up in the sky tonight and see if you can find the stars altair, deneb, and aldebaran - those stars and dozens of others were first categorized and named by arab astronomers. the milky way galaxy was first postulated to be an enormous nebula of faraway stars by arab scientists in andalusia (spain), even though this couldn't be proven until hundreds of years later when galileo had a telescope powerful enough to observe it and confirm that they were right.
muhammad al-khwarizmi introduced the decimal system into mathematics, invented algebra, more or less invented trigonometry, greatly advanced geography (building off the work of ptolemy) and accurately (for the time) mapped the world on behalf of the caliph. his latinized name (algoritmi) are where the very word "algorithm" comes from. he was a persian and did all his work in baghdad. again, he invented an entirely new field of mathematics - this is an accomplishment on par with isaac newton inventing calculus.
i could go on and on but this post is already getting way too long and i think (hope) that by now i've proven my point.
basically, for you to claim that emphasizing the vitality of the islamic sciences to the subsequent western renaissance is "revisionist/PC garbage" is laughably ignorant and frankly offensive whitewashing.