It appears he only has access to PS4 MP and XB1 SP - if the SP portion was better looking than the MP portion it wouldn't raise any eyebrows as that is was you'd expect.
The fact it's causing such a stir would seem to indicate the opposite!
Why is that the case? KZSF sp is 30fps. The mp is 60fps. I don't think you can automatically assume that the sp mode will be better than the mp mode. It kinda makes sense that the sp mode should be WORSE than the mp mode. In the sp mode, the console has to calculate the enemy ai. In the mp case, it does not.