[yShrike]

This is being said without knowing exactly which web sites you're talking about. You'd have to give examples to get a more precise answer.

Don't equate using something that works with following herd mentality. The reason something like Bootstrap by Twitter is used so often is because it "just works". If you are a start up with limited keystrokes before you burn out of money, then you focus on other value-generation parts of the business. I would rather get a halfway decent Bootstrap looking site (with tweaks) than spend money on a designer or time creating something that is different but I have no idea if it will convert well. In the meantime, I'll spend my time and energy on building new features. If the idea proves out, we'll loop back on the launch pages and do some A/B testing after the fact.