It's simple to whack up a HTML page with "hello world" printed bold on screen, yes. But then it's also pretty simple to do the same on iOS. If you want something quality then suddenly you have HTML, CSS, Javascript, PHP/Ruby/Python/Java, server tweaking, cross-browser hassles, graceful fallbacks and whatnot to deal with. It'll always be easier to create a crappy website than a polished iPhone app.

Not that I want to get into an argument about which is easier/harder. iOS is much harder for me but I have a 12 year head start with webdev.