I think it's largely signaling that a product or site is receiving attention from its creator or owner rather than trying to make anything look nice or work well. Can't let your online storefront look like it's from 2008, even if it's more usable than newer designs and loads 10x as fast, because people will think it looks neglected and possibly abandoned and won't buy stuff from you.
Most people outside tech don't really care. I've built a couple of webshops at a previous company... fancy loses customers.
Material design is merely a set of guidelines, and can be used as a common language for actually designing an application or website. The "actually designing" is usually the missing part.
Noone should expect MD to substitute thoughtful design.
If you're going to design though, you should design with your own distinctive style. Google has attempted to suggest that Material should be a universal design pattern, but that's silly: It's pretty much Google's brand at this point, given their tendency to slap it on everything, including iOS, where it makes no sense.
And the weakness of Material as a design pattern or common language is that Google's own apps and websites don't bother to consistently apply it.
