Actually it does if your gauge isn't a tight one on a project. Try making increases with KFB, M1F (or M1B) and a pulled/lifted increase and see the difference. The KFB creates a bar with nothing underneath it, whereas the M1F, if crossed properly, fills in the space much more.
I have never really figured out why the KFB is used except when increasing from a knit stitch followed by a purl-- then it fits in with the pattern. But other than that, the M1F is so much more discreet and hidden.