Most adblockers these days get rid of those messages as well. And asking you to unblock is not the same as stopping you completely - the only way to do that is paywalls.
Yes, but the point is, if they have the ability to ask, whether my blocker blocks the ask message or not, then they know I'm using an ad blocker, and they can refuse to serve me content, or redirect me to a subscription/registration page. But they keep on letting me view their content. It's their problem.
I don't think you understand the technicality behind it or didn't read the details above.
Sites can only attempt to ask by basically rendering that message and then replacing with ads. If the ads never load, then you'll see that message. However all these tricks are incredibly easy to get around with adblocker filters and so websites do NOT have a reliable way of knowing whether you are using an adblocker or not.
They can either refuse to serve content to everyone without a login (paywall) or serve it to everyone and hope the ads are there. That's how HTML works, the content is part of it and your adblocker is filtering it after receiving the content. There is no way for sites to refuse adblock users even if they wanted to without a paywall system.
You might look at this and think they still want you to have the content for free but they'd rather not - it's just out of their control unless they implement a different access model altogether.
