Bootstrap has a great impact since its launch. For a long period (2-3 years after version 2 was released) it was my number 1 choice to bootstrap and style fast a project. It was like creating fast mockups not in sketch or photoshop but with real markup and css. For sure its usage introduces some issues:
But you know what? It saved the day too many times. In fact since I am a web developer and not a pure designer, Bootstrap was the common language between me and the web designer for quite a few times. This made me feel safe because of some bad experiences before with web designers. We could discuss by taking some stuff for granted even for small things like grid's breakpoints which matter really a lot. Bootstrap made the communication better and easier. So all things mentioned above as problems are acceptable because of this.
For me the biggest issue Bootstrap has introduced is the fact that thousands of templates clones have been released during the last 3-4 years. This is very sad but so true. Many designers even today keep on reproducing the same recipe once again.
Huge companies have almost identical webpages because of this trend. For me this is what i dislike about Bootstrap most and it has to do with its great success. This is why i am rarely using it right now since i want to avoid this repetition of styling. What is the meaning of using Bootstrap if i have to override a huge part of it right? In fact i am using simpler grid solutions just for my markup's layout. I am really worried same thing will happen once again with material design. Am i wrong?