That's simply not true, Dog.
Indonesia is probably the only place I would not recommend-they've just never been too friendly to Americans.
As the Wombat says, the distances are probably the biggest issue. but one could spend years just exploring the Phillipines alone. Westerners, especially Americans, are genuinely liked and it is difficult to not have a good time there.
The recent unpleasantness in Viet Nam has not prevented visitors from being welcomed and enjoying a good visit.
Unfamiliarity with the peoples and culture may account for much of the reticience.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.