The point of the IPA is to have an international standard for phonetic transcription, regardless of the narrowness of that transcription. Individual authors can choose to specify or underspecify in their narrowness, for various purposes. Although this flexibility has not been codified, it’s not hard to figure out what works for you.
In light of this, I don’t understand why some authors continue to use APA or their own archaic, made-up phonetic alphabet that blatantly snubs the meaning of some IPA symbols. The point of the IPA is to be a standard. If you don’t need all the symbols, don’t use all of them. (Read: If you are a phonologist and only believe in one central vowel phoneme, then just use the schwa for all of them.) You can use IPA and do this. If you’re complaining about the difficulty in entering the characters, then blame the years of pre-Windows-7 PC usage, stop whining, and make yourself a custom keyboard. It’s actually easier on PC now than it is on Mac. Two things: 1. There are lots of ways out there to make phonetic character entry easier than Word’s Insert > Symbol. 2. If you are a professional that does this everyday for your job, push for your field to get its 21st century act together and develop a symbol entry tool that is designed for linguists. It might involve 5 keyboards. It might involve speech-to-text. It might involve a rubber band, a gumball, and a paperclip. There’s a solution out there. Needless to say, this is not an insurmountable problem that justifies continued use of arcane phonetic transcriptions.
For example, my historical linguistics text book (Hock and Joseph 2009) is still using a bastardized APA. The last update to the book was in 2009. The last revision of the IPA was in 2005. Hock is ancient, but I don’t know why a prominent linguist like Joseph would feel comfortable with Hock’s treatment of phonetics/phonology. Maybe he couldn’t convince him to use something else… Maybe the convention is encrusted onto historical linguistics. Regardless, my classmates – and even the teacher – are having trouble dealing with Hock’s now-rogue transcription.
People really need to get on board with the IPA. It’s the international standard. Use it. If you have critiques, change it from the inside. If you don’t need the plethora of symbols, just use the ones you do need. Moving forward is the answer. Looking backward and whining about change is not.