Do I understand his points? Sure, and they're valid; but I don't think his review is in any way reasonable.
To me, a 4/10 game is something that is not functional, something that is so trite and broken that you cannot possibly play through it without some kind of forcing of the will. Bioshock Infinite's combat does indeed become repetitive; but once you master it, it's fun - I had a blast with the last few hours of the game because I finally felt in control. Beyond that, I could always appreciate the tremendous amount of work that went into the art and programming for the game, the story was also something I really enjoyed - even if it had bizarre moments that I didn't totally love (the theatre scenes, for example).
The short version, I think 4/10 is a completely unreasonable and incorrect score to give the game. Sure, you didn't enjoy it; but that doesn't mean that it is poorly made.