Yes, and I think this is strange, because this exact feature is how I introduced my friends to the original Starcraft. More than half the fun of an RTS for me is playing it on a LAN with a few of my friends. Some of them even went out and bought the game afterward. If an RTS doesn't let me have a lag-free LAN experience, why should I buy it? How should I convince others to buy it?
Forcing everyone to have a unique key for Starcraft seems like a good idea for Blizzard on the surface, but I think that, in the end, it will hurt them more than it will help them.