Inconsistency with -a vs -A

I was curious if there was a reason that some command use -a and some command use -A. For example, to view all branches the lowercase switch 'a' is used, but when staging all files with add an uppercase 'A'. Of course I always pick the wrong one when running either command. Is there a reason for the inconsistency? Do you think they should be made the same?

Thanks! Bradly Feeley