You seem to miss the point that many of those sites wouldn't have been launched in the first place if a way to make it look half-decent, fast, wasn't widely available. Making a website, especially a web app, takes some breaking inertia, if you've ever tried you'll know, and anything that helps you in getting it out is one step further from not launching at all. Given popularity, the design can be amended. A non-launch has nothing to amend, and is, if nothing else, a tiny loss for the web.