> Especially as the price approaches four digits, "what if this gets stolen?" has to be near the top of most potential buyers' list of concerns and probably chills sales to some degree.
If you're spending that much on a bike then you're cycling regularly (communter and/or every weekend type). You're not going to ride a shitty bike if you're riding that often. Bikes aren't like cars -- a Corolla will get you from point A to point B just as well as a Cadillac, but a doubling in the price point of a bike (esp. 500 to 1000 range!) has a massive impact.
Of course there are people who buy racing bikes and ride them a few times a year. But those people rare enough that it doesn't make sense to spend the money designing and stocking a product just for them. And anyways, the guy on the sales floor is probably going to be the most important factor in their purchasing decision.