[Aloha]

I'd actually argue that Aviation is the outlier among Part 90, Amateur, and Public Safety users. The general rule in most radio services is using both phonetics and not, as to try to balance intelligibility and communications density.

[HNisCIS]

It's an outlier because typically the comms cycle is very fast and only a single cycle. The radios are also quite bad and there isn't room for errors that you'd normally correct naturally in the context of a longer conversation