I have to report that I am guilty of having cases of unopen army builders, but with me, its just because I have not had the time to open or display them.
As a matter of fact, and JediMac can attest to this, I just pulled all of my army builders out with the intent to open them because the packaging is taking up too much room. I haven't done it yet, and now I'm using the mass opening party as a reward for finishing a certain project.