I recently looked into "what if I flew to Hawaii?". Maybe I should fly HA? If so, it looks like flights within Hawaii can be credited to many US programs and Hawaii to Asia and the South Pacific can be credited to AA, but if you fly between the mainland and Hawaii, you are limited to HA's program and B6 in some cases.
Seems to be you can earn miles on Korean Air, Virgin Atlantic, and Virgin Australia for Hawaiian flights but many Americans don't regularly fly those airlines or credit flights to those airlines.
I wonder if flying HA is worth the experience? I heard the meal is free but not that good.