I think the woodworking obsession might be caused by the lot trait, "Homey."
As soon as the new lot traits came out for the base game, I installed "Homey" and my sims were constantly making sculptures (oh, come on guys, you know how to make the camping mascots!).
I've removed the Homey trait just now, so we'll see if that changes things (then I won't need to keep the woodworking table locked up).