I see this line of thought floated a lot. Go build a fully dynamic app used by internal teams with just those three tools and tell me how it goes after you've been maintaining and building on it for a while.
Those are good building blocks but they're simply not sufficient if you are building a 'Web App' and not a 'Website'.
Also I'll cut off the inevitable, "The web was not built for this and it shouldn't become a place for apps." The world disagrees, I disagree and most people developing on the web disagree.
And I'll raise that we should be moving more towards the web being the best universal distribution platform for software.
