I really don't think the excuse that they don't know is thin. It's not very visible on the forum and the thread that explains it (linked here in my post above) isn't very clear (it's been rewritten a bit I see, but still). Especially the part that the 'receiver' has to visit his town after every tap to get the stacking going on confuses a lot of people ("I tapped 3 times but he only receives 1 hand?? " ) and maybe they don't see the point in going through all this trouble?
And then I also came across someone saying that sometimes people aren't even able to tap said buildings (as in, there is no icon to tap on). If this is actually happening, then you can't blame them either.
I just want to give some sort of counter voice, even though I am a big proponent of the whole staggering strategy (feel free to add me, I always tap on the stagger buildings!).