Blocking ads is morally OK only as long as that's the only way to consume that content, and as long as you're not trying to block anti-ad-block warnings.
If there's a reasonably priced subscription available (or another business model), and if the publisher doesn't want your eyeballs while you have an adblocker active, there's no argument you can make for the morality of adblocking. It's your computer, you can be selective about what you execute on it, but the publisher should also be free to reject your visit.
Blocking YouTube's adblock detection legitimizes all the changes that Google is making in Chrome, being why we can't have nice things. And it's similar to extensions designed to workaround paywalls, or software piracy. Sooner or later adblocking will become illegal.