If you judge this for being a bad AC game, you're right, it definitely deserves a 6. It's the worst in the series.
It manages to sum up all the rehashed gameplay and other ideas that didn't fit in previous games because they were either annoying or uninteresting.
But if you think a little, this is a nice console port and at least the graphics on PC look great. So it gets a 7 if you judge it from an ordinary game perspective.
Now, being an AC fan, I'd like to say the main downsides of this game: the story is bad, and the main character is not likeable at all, so I wasn't immersed throughout my 9 hours walkthrough. Also, the dialogue and accents are really awful. The collectibles are here, but they're plenty and useless. The pop-up tutorials that appear way to often in the right corner are definitely the most annoying things. The missions are way to repetitive, rehashed and I just wanted to finish them already. Even the soundtrack is not so great, I had high hopes.
Found only 3 things interesting:
1. a nice trading system;
2. you can play as three personas, which adds a little bit more variety to missions ;
3. the fact that Ubisoft released this on PC, and it's not that broken game everyone expected.
I wouldn't recommend this, is skippable, but if you are bored, and already beat all other AC games, you could try it.