I guess you have to alter the definition of MMO, it's a single player game with some co-op options - the only MMO aspect is that other players now influence your game and if you go full online mode you can interact with a handful of other players at a time. There's no lobby where you can see everyone else jumping around your screen, you don't go on raids, no crafting or massive guilds or player created factions.
If you expect to see a linear progressive mission based space game with cinematic cut scenes this isn't your game. If you expect a massive PvP arena based space game this isn't your game.
I would consider the "Retail" release an early access, it's complete enough to call a game if you hold it up next to the original Elite but there's plenty left for them to add and work on.
Some might feel that its design is off putting when compared to today's play to complete the story gameplay but it's faithful to the original "space simulation" of having an open galaxy to explore and fight in with no defined ending. A more modern approach would have been to make Call of Duty with space ships, I'm sure any other publisher would have made it that way.