This is so sad to see. If you read the comments on My Anime List it's quite obvious that it's a terminally-online contingent of extremely salty "fans" who are pure raging that the anime didn't adapt every scene 100% precisely how they wanted it to, so they've rated it 1/10 out of spite.
Hard to even call these people fans. They don't really give a shit about Shenmue or the future of the series, they just live to moan.
I'm glad to see the vast majority of Shenmue fans loved the first episode, and from what I've seen most people unfamiliar with Shenmue / those who haven't played the games seem to love it.
Cruncyroll ratings are much more reflective of people's actual opinions on the show.