Not saying you are wrong but I usually don't need to stop and think when I see "login" but I always do whenever I see something else. English is kinda easy to understand, even a "pull" or "push" sign on a door is easy to understand but it doesn't get easier than having the handle only on one side of the door. I'd apply the same logic to "login", using whatever everyone is using even if it's not correct or making the most sense.