I'm surprised no one has made this connection sooner. I guess it's because for the most part, the Brady agenda has been largely unsuccessful outside California and a few other anti-gun strongholds:
Choice, and the two faces of the Brady Campaign - St. Louis Gun Rights Examiner Kurt Hofmann
Essentially it boils down to the Brady Campaign being all for the rights of property owners when it comes to banning guns from their property, but when an organization (Starbucks) makes the choice to allow guns on it's property (essentially being consistent with the local laws), the Brady Campaign demands that Starbucks ban guns.
It's a classic case of "Pro-choice as long as it's the choice I want you to make".
This is no different than the Brady Campaign's position on "states rights". They are all for states rights when it comes to banning guns, but if a state wants to allow guns, they seek to use federal legislation to override the state.
So why is the Brady Campaign being hypocritical? Because they don't care about property owners rights, states rights, or anyone's rights really. Their goal is to prevent as many gun owners as possible from carrying guns.