The importance of “water is wet” studies should not be understated. Because now you have a study to point to when someone who doesn’t already know this asks you for a source, as opposed to relying on anecdotal evidence or “common knowledge”.
Here’s the thing about “we knew that already.” Plenty of racist white folks “knew” exactly the opposite. And to people who are just clueless, “here’s the receipts” is a lot more convincing than “you should believe me and not them because I’m right and they’re wrong.”
Yeah, it’s frustrating, but it’s 2018: what ISN’T frustrating?