Is there some balance reason for it? Even if DDs didn't break root, root rotting would still be superior (because it's more efficient), and that works fine for druids/necros. Wizards aren't loved in groups on early TLPs. There are only a couple decent quad kiting locations, and they're not in zones with multiple picks. Allowing them to root and nuke would give them more options. I don't see why it doesn't work.