They shift things around because some "Corporate Wonder Child" came up with an idea to increase movement through the store so each aisle has more "exposure time" and customers stay longer in the store while searching.
It's all about "Merchandising" (aka making people hunt for stuff and creating more impulse purchases).
Otherwise, why do you find coffee filters in the pet food section? Sodapop next to the detergents? Bacon 100 feet from eggs and butter?
Also, "companion" products next to each other in some cases (e.g., sugar next to coffee and tea, vanilla wafers next to bananas, etc.)
Also, major more expensive brands put at eye level with cheaper brands low on the shelf...
The "changes" also increase customer purchases for those confused shoppers (without a list) that wander down every aisle, contemplating every item, every shelf, etc. It becomes a "Treasure Hunt" which results in higher $$ at the checkout stand...