Sure, "yo, I'm leaving", "yes sir, here, let me stamp your passport."
Well, yeah, that's what immigration is, most of the time (at least with my US passport). The UK, the US, and Australia give a bit of interrogation at immigration (and the Canadians do to Americans whatever the Americans DHS does to Canadians citizens, entirely justifiably), but Chile and the EU just open and stamp the passport, both on arrival and departure. I can't speak from experience about anywhere else. (And GP is right that I was wrong to call what they do at exit "customs".)
That's not a barrier to leaving a country, and it's not "customs." Requiring you to be fingerprinted is a whole different league. Interesting that this story shows up alongside another today where some cancer patient was detained because they couldn't get a good set of fingerprints off him. I actually just got back from a conference in Hawaii with this guy who got hassled at the border because he climbs and his fingerprints aren't all they could be.
Yes, requiring foreigners to be fingerprinted is a whole different league, something I've written my elected officials to complain about. (The people directly affected can't do, which is why it probably won't change.) That doesn't mean that the exit immigration check that most countries do isn't immigration.
As GP suggested, the US has, until recently, had essentially no idea how many visitors overstayed their visas. I don't see the problem with that old approach, in general. Exit immigration is fairly time-consuming, mostly standing in line.