It's a bug if it behaves contrary to the programmer's expectation. Full stop. There is too much diversity in users to go the other way on this. If a product do

It's a bug if it behaves contrary to the programmer's expectation. Full stop. There is too much diversity in users to go the other way on this. If a product doesn't meet a user's expectations it may be a poor fit, improper usage, or even a braindead terrible design, but these are not bugs.