Utterly spurious. The toolmarks don't match the experiment and therefore it was another civilization? Just stupid. They may have used a different type of grist for their drills. They may have had a technique for smoothing them after the hole was cut. They may have just been so practiced in their art that they were just better at it than anyone who tries to replicate it today by guessing. We have unequivocal evidence that cutting and drilling granite with available material was totally possible. We don't know and probably never will know for certain how exactly they worked. But it's 100% plausible they did it themselves with technology and resources available at the time that matches all the correlated evidence. There are carved granite and schist artifacts in Egypt spanning thousands of years during which they kept lots of written and artistic records and interacted with dozens of regional cultures all of whom are well-attested. Accusing the scientific mainstream of being to stuck in their orthodoxy to accept an alternate theory is rich coming from someone who believes a wildly implausible theory with nearly religious fervor and rejects all the physical evidence in front of his face in favor of blind faith. Bring some proof beyond pure conjecture and then maybe we'll be convinced. Go read about pre-Clovis people in the Americas. The orthodoxy that had stood for decades was upended pretty quickly when new evidence was uncovered.