First, OE tires are built to the vehicle manufacturer's specs - and frequently, what the vehicle manufacturer wants is NOT what the average consumer wants.
The average OEM wants a tire that is great for rolling resistance, which is obtained by sacrificing treadwear and grip, especially wet grip. The average consumer wants a tire that wears good to great, has good grip, and they will take fuel economy (rolling resistance) if it doesn't sacrifice the wear and grip much.
In this video, BMW is not the usual OEM. My experience with them is that they want good grip, and don't care much about wear and fuel economy.
I don't think Mr Benson did a good job of explaining why this test was an anomaly when it comes to the question about OE tires. In fact, he didn't mention how weird BMW is at all!! What I think is that Michelin used Mr. Benson as an advertisement. What Mr. Benson got was a video at a low cost. It's a win/win for those 2, but a loss for the truth!