"They are facts. The question is whether they are important?"
Yes. Absolutely. They are and always will be.
". The majority of users now are consumers of web content. To them the important thing is does it work reliably? Can I access the content I want? Is it easy to use?"
That may be what the average consumer cares about, but it doesn't change the fact that being able to use their device as they choose is important. Just because the majority wants something shiny and isn't ever going to tinker with it doesn't mean that the ability to tinker is unimportant.
Let's look at some other things that are true by your argument. Most people wouldn't be affected if the use of a five button mouse were suddenly removed from Windows, so that woludn't be important. Most people wouldn't be affected if Windows were the only OS available, so let's just do away with all the others. Most people wouldn't be affected if international calls were suddenly impossible, so lets do away with that capability (maybe to help curb terrorism). Most people don't have any secrets that would be harmful to them if the government knew about them, so we don't really need laws restricting the government's ability to listen in on our phone calls.
See where that kind of thinking leads?
"Only the true pistonheads think so."
So very, very wrong. No one who knows me would EVER classify me as a piston head. A couple of them actually cringe when they see me in an auto parts store by myself. Even so I sorely resent being forced to pay a mechanic to fix a problem that I should be able to fix by myself just because some idiot decided that my car needs to be computer controlled. Very few people I know would disagree with that sentiment.
The computer in cars added little of value. They just make for more complexity and more things that can go wrong. It's the same thing with the lockdown on mobile devices: little or no real added value for the consumer, but lots of things are taken out of the user's hands for no good reason.