Oh Tony, come on! Don't come with the unprofessional crap! It happens.

I have landed a few times without talking to tower in ATL. Almost every time it was workload related, both on my part, and the controllers part. Often, there is so much radio congestion there, Approach forgets to hand you off, and you forget to do it yourself at the marker (or nobody can get a word in edgewise... too many "windchecks" .) Other times it's a PRM and you're fat, dumb and happy since you're usually cleared to land 18 miles out there, except this time you weren't. Also there's times where they rush you due to spacing, say 200 to the marker on an ILS, and it gets real busy over the marker configuring and reading checklists, you forget to switch.

ATL Tower recognizes that this happens here, and for years, they have briefed pilots at the meet & greets that "in ATL the green light is ALWAYS on". They make it clear that if this happens, they want us to land, not go around, which actually may cause a conflict with a departure if they aren't expecting it and you don't announce it (being NORDO) since we have 5 parallel runways. If you land without clearance, you just exit the runway and contact ground. It's really not that big of a deal at a major airport.

Consider this:

ATL is departing a turboprop on 26L on a VFR day. They get a 350 heading ASAP to clear the path for an RNAV jet behind them (very typical). Arrivals are landing 26R. While departures are staggered with arrivals to provide a buffer, on a clear day, with good spacing, TOWER EXPECTS YOU TO LAND. The t-prop turns out over 26R at 400 feet (typical), and you go around at 500' because you just realized you didn't contact tower. You punch out, and the procedure is straight out to 1500, the RT to 360 to the hold. You are now right on top of the turboprop. Loss of separation occurs. Now you are surely violated if not dead.

I'll take my chances with landing on a runway that is 99.9% sure to be clear, even without landing clearance.