believe me: i deeply understand what's happening here; when i did del.icio.us there were hundreds of copies. because they did not understand the core decisions, they generally went down the wrong path.
I've felt this pain deeply as well, and a non-technology company. Founding one of the earliest successful coworking spaces, lots of other "shared offices" have popped up and even Regus has co-opted the term coworking and the physical attributes of a coworking space without considering the underlying decisions or core values that we've established.
You nailed it. Did they change the constrained iOS UI for the better? Yes. Do they want to see their menu pop up in every new app? Maybe no.
But they clearly resolved an issue that many people have had for long. And we are thankful to them for that matter.
I will sure look upon this code to see if I can get some inspiration.
Remember, some painter said: "Good Artists Borrow, Great Artists Steal"
improving upon is cool. copying is lame.