Interesting! I've seen this happen a few times, though I've never witnessed something as extreme as a 10+ minute wait just for the off-ramp. I still maintain that it seems dangerous regardless of the situation, because while someone stops and tries to cut in line, the non-off-ramp lane they're stopped on can still keep moving, creating opportunities for collisions.
It's more common in larger metro areas - NYC, LA and Atlanta are infamous for it - but can happen anywhere depending on what is going on further down the exit lane (an emergency vehicle, car breakdown, etc).
Chicago's Lake Shore Drive/Belmont intersection has 3 stoplights you have to pass to get out. During rush hour it sometimes gets so backed up my bus has gotten stuck in it for a half hour. The first light is for the northbound on/off and a small side street that goes to some tennis/etc courts, the second for southbound on/off, and the side street adjacent to LSD splits in two so the third light is for the same street as the second light and is where you can finally enter it.