libpd/libpd — comment on commit 01492deb9cdaae5acf0c2d009c13f3fc7d423d1c
File: objc/PdAudioController.m line 93
By reakinator:

It is more of standard practice than anything else. It is very easy to argue that in this case there are no side effects, but when the code gets older and more changes occur, you no longer have one centralized place where the ivar is set. It ends up being a mess and the root of many hard-to-find bugs.

About finding overridden accessors, you normally group them in the file and just look for them first. It's pretty standard.