Yep, the market has changed. So what? I will not ever own an "adventure bike". They are fugly, period. I do not, and will not ever need offroad, or even dirt road ability. Not in my mission profile. Regarding the statements that sport touring bikes don't offer enough performance, that the adventure type bikes do it better. Maybe. But do the adventure bikes offer a 250+ mile fuel tank, really good wind protection and nicely integrated had bags? To my mind, if I have to figure out better wind protection and storage, I've bought the wrong bike. Looks like the other performance bikes mentioned just canyon carving rockets with hard luggage. Sounds like fun, but will my wrists, hips and knees tolerate it for hours?
Consider also the cost of manufacturing. AFAIK motorcycling worldwide is becoming less popular. Emissions regulations are getting tougher. Manufacturing a 4cylinder, shaft drive, full fairing machine with hard bags is going to be a lot more expensive than a 2cylinder, chain drive, half fairing ( or less) with optional hard bags. Settling on one two cylinder engine family that can be used in multiple models, sharing parts, and more importantly, emissions controls, has to be a huge financial driver. Just look at the pricing of the few remaining traditional sport touring machines VS the ADV's. If I had to guess, there is more profit in the ADV's.
Call me a cynic, but markets may be based in demand, but demand can be manufactured. Used to be magazines, now its online, but reviews and reviewers are paid for. Social media is sponsored. The manufacturers are happy to sell something with a higher margin. And then there is the "look", the "lifestyle". Take jeeps for example, I see them everyday with offroad tires, jacks, winches, etc. the large percentage of them will never see a dirt road.
I'm alright with being a dinosaur. I'll soldier on with used machines as long as I want to ride.