Grocery stores are stressful places with lots of people where you want to be in and out as fast as possible. So you develop a routine that helps you to do it as efficient as you can.
When they move stuff around it's not the changes as such that give you trouble, it's that you have to change your routine, and that takes time. And because you are in this stressful place full of people it can take a longer time to adapt your routine.
If, every time you go to the store, they would empty the store for the whole day, just for you, so no time pressure, no people, you wouldn't mind if they changed stuff around. You'd take your time to find the new location, maybe even remember it faster, and you'd also examine the stuff that's now occupying the location of where the things you want used to be. Maybe even think about it it's something you need. Having stuff turn up in unexpected places can make you revaluate them

I just realised that I made a generalisation when this may just only be how I personally experience this. So ... Just replace every "you" with "I" ... Sorry.