We have shitloads of them. Squarespace, Blogger, Wordpress, on to new hotnesses like Macaw, Dreamweaver, on and on and on and on and on and on and on and on...it's really pretty insane to argue, in 2014, that we have some kind of lack of simple-to-use website-creation things.
If your response is, "Sure, but they can't do anything complex/building interactive experiences is still hard" well, we had Flash, etc, but also, at some point this is moving the goalposts so far as to constitute meaninglessness. If what you're asking is, "why isn't there a simple-to-use WYSIWYG editor that I can use to build anything I want," then my answer is, "it's riding on the back of my unicorn."
We aren't talking about sites (that would be the equivalent of DTP), but apps. Hypercard was used to author content, sure, but also create games, tools, and so on. I don't think that is moving the goalposts at all.
If your response is, "Sure, but they can't do anything complex/building interactive experiences is still hard" well, we had Flash, etc, but also, at some point this is moving the goalposts so far as to constitute meaninglessness. If what you're asking is, "why isn't there a simple-to-use WYSIWYG editor that I can use to build anything I want," then my answer is, "it's riding on the back of my unicorn."