I believe the point is the wheel lines and to vary where the wheels go by changing the pattern each time you mow so you don't, for example, always drive exactly down the fence and cause a rut or mulch buildup or missed area.

I dont think it was "don't hurt the grass while you cut it" or "mow it four times in one sitting".

How often are you people mowing your lawn that that's even a concern? It's like this is "surburbs: the problem: the comment section"