In the 1990's when HD was kicking butt & taking names (on a multi-month waiting list to buy bikes), they were riding the wave of a healthy economy combined with an AGING population that was growing (baby boomers) with disposable income. So they made a LOT of bikes & a LOT of money. They continued this into the present century, and then the economy got slower, money dried up as jobs dried up, and HD sales are a reflection of that.
If the economy roars again (not likely with the bozo debt crew running the fed store these days) then HD sales would be better than they are now. As it stands, other than maintain their infrastructure as best they can & pay down/write down their own internal problems, it is not very likely that HD will sell big numbers again anytime soon.
The last few years - ABS, new frame, new suspension, new engines, new transmission, throttle by wire, etc. have seen a lot of changes from a company that is known to be slow to change. Expect to see more changes to the product line. I know a number of folks who bought bikes just to get ABS. For me, it was a no brainer.