Very often in the maintenance and repair world, the easiest jobs become the most annoying. It's understandable when the pain is caused by some mechanical error. A bolt head sheers off, wires in a box are too short, or someone mushroomed a shaft and now the bearing is stuck. These are normal levels of annoyance that at some point become achievements for fixing, and a point of pride when others ask you to teach them how you've done it. Then we get to building shelves.
Wire rack shelves are not that difficult to build. On a scale of 1-10 on the skill required, I give it a 2 tops. Where they become not so easy, is having to build them for someone else with zero other information provided. If you stay at any job site long enough, it's almost guaranteed you will make these shelves. You may even have some in your basement, garage, or apartment.