It does make it unplayable. And if they made it impossible to alter anything else on the map besides belts, I'd imagine they could remove the ability to undo wires, since everything else is something you can't move.

Well yea, I'm not going to, but doesn't this still count as a bug?

If you shift-click on an electric pole in transport belt madness, the pole will disconnect itself from other ones, effectively forcing you to quit and open it again.