Wow, this thread has gone places I never imagined.
We just got back from a week exploring the Washington & Oregon coast. I can safely say that I saw people taking both approaches. Personally, I removed the hitch most of the time, though I did leave it one one day.
Here's my reasoning for taking it off:
1) traveling with friends parked in next space, needed room to walk between truck/tongue without getting shins bashed/greased.
2) Short space, needed to get truck bumper right up by the trailer tongue so the truck didn't impede traffic.
3) No locking pin, don't want it to walk away.
4) Driving on beach - didn't want the salt/sand all over it.
Why I left it on the one day:
1) Friends had headed home
2) Last day of trip
3) Planned early departure