We don't have a Joann's, but we have other stores that have done this and it annoys me to no end! When I worked retail, inventory was done after hours because then you didn't bother any customers and, more importantly for us from an inventory perspective, customers didn't bother us by picking stuff off a shelf and leaving it somewhere else in the store lol

The worst for this in our area is Walmart! When they are open 24 hours for the three weeks leading up to Christmas, it's expected that if you go late at night they're doing inventory because they have to do it at some point and being open 24 hours means no time without customers in the store. But I guess because people tolerated pallets worth of stuff blocking aisles so well during those three weeks they decided they could pull it off all year. We have FOUR Walmarts, soon to be five, and every one has pallets worth of stuff blocking aisles. Where there used to be gaps between the large displays so you could get to the other side of the aisle there are now huge pallets wrapped in plastic. Dumb, dumb, dumb and annoys me EVERY time we go! And last time I went they had their fabric section blocked off so bad you couldn't even get in. Don't they understand I need fabric?! lol And don't get me started on the missing price tags on shelves and large pieces of paper taped up with their new display schemes all over the place...