Agreed but the only reason this exists is because people are lazy. It's not hard to make a Bootstrap site look nothing like Bootstrap. The problem is people put a site up and focus on the backend and consider the front-end solved because they use Bootstrap. That's the wrong way to look at it. People need to realize it's beginning to look like they are just using the default WP or Tumblr template when they do that. If you wouldn't do that for your personal blog, why would you do it for your companies website?
Take a bit of time and style it at least. Change the colors, put a header image on it - something. Anything.
Very good advice, but I'm going to take the curmudgeon level +1.
Or... take a little more time and actually learn CSS3 and media queries... then write your own style sheets. It's really not that hard and you'll end up with a style sheet where YOU KNOW every line and every class. When you get there (again, not really that hard), it's faster/better than SaSS or LESS. Seriously.
Take a bit of time and style it at least. Change the colors, put a header image on it - something. Anything.