Well, he buys them for the same reason people buy Apple products: very performant, look good, and carry a lot of social status.
Otherwise, they make some very questionable engineering decisions for sure. On their motorbikes, you often have to disassemble half the bodywork just to change the battery; that's just beyond stupid. But like Apple, their products are kind of unique, so people deal with it.
BMW bikes have improved. It used to be with the last of the dry clutch flat twins that when the clutch failed (and it would fail), you had to remove the back half of the bike. Literally. As in not figuratively, to avoid doubt. The front half would be left standing, like some bisected cow artwork. Apparently it was a two day job.
I mean, they are generally excellent motorcycles. Their monocylinders are super smooth with great handling.
But often you have to deal with those weird engineering decisions that make repairs annoying. My local garage is a BMW car specialist, and it appears that it's basically the same deal.
Funnily enough, in my youth I visited the BMW factory in Munich, and I was amazed back then. But the maintenance fails to amaze as much, haha.
Otherwise, they make some very questionable engineering decisions for sure. On their motorbikes, you often have to disassemble half the bodywork just to change the battery; that's just beyond stupid. But like Apple, their products are kind of unique, so people deal with it.