It would be the same for the browser user agent, but a lot of other user agents might have trouble. Anyway, why are you advocating a change that you recognize will have no effect?

? The change I'm advocating is in browser behavior, and would definitely make a difference for any site that complies with HTTP. There's nothing preventing malicious hosts from continuing to serve pages full of ads, but then, there never was.

It sounds like he is claiming that if a major browser changed this behavior, websites would just reconfigure their response to give a 200 response error page because they would prefer if the browser showed something like this rather than a browser dependent error message. That would end up making 404 completely useless, even for actual tools like wget because it would be against webmasters interests to use them anymore.

Do you disagree with that claim?

Well, my counterargument is that a change in browser behavior would make sites more usable, encouraging the proper use of 404. Of course, if that weren't the case, I'd agree there'd be no point in changing :P

If webmasters wanted a spartan base error they could easily have one though.