Why doesn't Hawaii and Arizona participate in the daylight saving time?

The exception is the Navajo Nation. Most of Arizona has no Daylight Saving Time. With the exception of the Navajo Nation, Arizona does not use DST. With the exception of the Navajo Nation, Arizona does not set the clocks forward 1 hour in spring for DST with the rest of the United States and that is why there is no day light saving time

They simply think there's no reason to.