When Google introduced Material Design, it made a big wave in designer community. They put bits and pieces people have used for years into a consistent visual system and gave it a fancy name. As we should have expected, designers are crazy about it and they are using Google's Material Design for everything.
And they are doing it all wrong!
While Google did a great job to develop their own design metaphors, it's clearly that Material Design is made by Google and only works for Google's products. It wasn't designed for you and me. Design is not something we can generalize. Brands are not the same and they need different languages to voice their messages. If we put all the Material Design things on Facebook app, it will no longer look and feel like it's a part of Facebook's brand.
Design language will be the next movement in digital design. Learn, be inspired, create your own design language that consists with brand; stop making the Internet look like Google's.