Something like "the web will never be the dominant platform, except for the past 10 years and the next 10 years" does lack a certain punch, but at least it would be specific :-)
(And I appreciate your taking the time to write your blog post, and don't want to be a jerk, but the definition of never is "at no time in the past or future; on no occasion; not ever," so maybe you could rephrase to something like "the web cannot continue indefinitely being the dominant platform," which at least acknowledges its current strength.)
I was trying to convey that the web is always going to have to fight for its survival, contrary to the common assumption that the web has some magical properties that ensure its long-term prominence.
Whenever I see these "the web isn't as good as native" discussions I always think back to the late 90s when web-based email took off. How was the user experience on Yahoo mail in 1998? It was full page refreshes on 56k modems. The web doesn't have to maintain pace with native to be relevant, or even to win. It just has to keep being the easy, ubiquitous platform it is today.