Sone years ago, the news did a segment about some of the "Big 3" manufacturers weren't allowing certain brand combinations. Dealerships were being told what brands they could and couldn't carry at the same time. It may not be what's going on there, but who knows.
Dunno. They were Honda (51 years) and Suzuki (30+ years) before HD. Probably steered their energy towards the higher margin products (more money on the table on an E-Glide than on a Big Red-remember those? ).