You are correct about the price of some of these bikes. When I first started riding it was because it was the cheapest way to get around. Today it is a sacrifice you make for the love of riding.
And that there IS THE ISSUE.
When I first started riding in 1978 it was because
1) The company I had obtained a job with canceled the works bus. I needed transport.
2) I could not afford a car. And was still learning to drive.
3) You could ride a bike alone on "learner" plates.
I had no interest at all in bikes before this. I spent my money on shooting.
Here today the only real "consumer grade" bikes are scooters. But you can get a decent small-medium sized car for the price of a decent sized scooter - so unless you have a parking issue - many will simply get a car. It's easier/better for picking up chicks too. And I'll bet the insurance is less.
It is also quite an expense here to get a Bike license - It's a whole new exam - and frankly if I did not already have one - I would not use the money to get a license.
Bikes have ceased to be (in the main) practical. You cannot really home maintain (cost again) as more and more restrictions are applied.
Depending where you live this can make even moderate customizing a chore. So the old adage of it allowing you individuality fades.
In cities many potential scooter riders get bicycles - traffic free cycle routes promote this. Though here bikes do get to use bus and taxi lanes.
The world has changed. Folk generally have less cash for toys. So they get affordable toys. That or certain toys have become "essential" - Think iPhones, iPads and their Android equivalents. Bikes move down a notch or 6.
I have owned a Harley - it did its job well - but did not do what I needed from a bike then. Today - still not, but in 5-6 years - maybe.
But that bike will be hard to find in 5-6 years. And tbh my currently 38 year old Guzzi will do it then just as well.
If my missus had said outright back in 2010 she really did not want to travel on a bike any more - frankly I would have kept my 1997 Buell S3T and never bought a Rocket. For solo use the Buell was (and is) better suited to my roads. Was better handling, bigger tank, no electronics worth calling, better consumption and more than able to maintain the highway speeds I need/want. But the missus said yes, and so we needed seat space. Life is sometimes incoherent.
I don't know what it's like elsewhere - but here there has been a massive change towards mid-sized bikes - even small (physically). A lot of older bikes have gained in price as they become more and more sought out because they are cheap and easy to maintain. I have a mate with an "all makes" workshop and much of his work these days is Functional Restoration of older bikes. A lot of Guzzis and BMW's but also mid rage Jap stuff and some Triumphs. And I have not seen a youngster in his shop in years (except his nephew who works for him).
Simple fact is - IF YOU WANT A HARLEY - AND HAVE THE MONEY - YOU WILL BUY IT. If you don't want one or don't have the cash - then you wont. No other justification is required. If I had 45 grand to spend on a vehicle - it would not be a bike.