I don't expect an employee of a big box store to have the knowledge or passion for something like model car kits nor do I expect them to seek out employees who do. I do expect a hobby shop to have knowledgeable people though, as that is their specialty. Having worked in retail, the concept of "facing the shelves" entails filling empty slots to give the impression of not being out of stock. Many times it is because management is coming to visit and they can't tell a '69 Camaro from a '69 Mustang, but they do see an open slot on the shelf.
If I have to look around a bit at Hobby Lobby to find what I want, then that is fine with me, it's a huge store and they have lots to tend to, like getting the Christmas stuff out by the fourth of July.
If it bothers you that much, then stop and take a minute to fix it, I am sure the workers would appreciate the help.