You're quite right, especially in the Goldwing category. There are many, many Goldwings out there with 100K, 200K and 300-350K miles on them and the motors haven't been touched, other than maintenance. I don't have anything against any brand motorcycle, (other than being LOUD when they don't need to be)(and that's the owners fault, not the bikes). One chooses what fits them, what appeals to them and or, is guided by input from multiple sources of experience. It's just that, I don't seem to see many Africa Twins on Adventure series shows or youtube vids. It seems that, at least for the ones I've watched, it's mostly BMW's.IMO Honda has been producing motorcycles capable of 100,000 plus miles since the introduction of the CB750K in 69. They fit right in to the reliability and 100K club.
The BMW Adventure bikes might be great machines for sure. Although I've owned a few other brands, I've been a Honda guy for most of my life. Heck, I've got a BMW K1600 GTL-E that I use for pleasure cruising and it's so far, an outstanding bike.