Can someone explain to me why all this faces are selected by a single faceloop?

I had something similar, but not entirely the same. It looks like one of the face loops goes around the sphere and connects to the face loop next to it. Kind of like a spiral. I don not think it matters too much, but it does make adding and adjusting edge loops a bit more annoying.

It makes sense if you look at it from the left/right side view from where the face loop start (because of the 3-pole). Just follow the face loop up and around until you get to the top view. At the top view it loops around itself at the peak of the mesh detail and then goes back down around again in the opposite direction. It then ends at the opposite side of the left/right view that you started from.

If you want to break it up, you would need to add some poles to intersect the loop.