Of course logic exists, but no one uses it.
As an experiment, I have tested various sayings and words. For example, UK and NZ people say they take a "maths" course, whereas people from North America say they take a "math" course.
Which one is better? Quick answer - neither. Words are arbitrary by nature and it doesn't matter if I call something a "blork" or a "bleen" as long as we all know what we mean.
However, note that all NA people take the "math" side and try to justify their use, and all the NZ/UK people take the "maths" side and try to justify their use.
The same is true for every other arbitrary spelling or wording there is - so, "boot" versus "trunk", "colour" versus "color" etc.. etc....
Even though we know these are arbitrary examples and don't really matter, emotion come out and I am amazed at how certain everyone thinks they are (Read "On Being Certain: Believing You are Right Even When You're Not" by Robert Burton for a very cool discussion of this phenomenon).
Imagine what happens with more complex issues, like capital punishment, legalized abortion, legalized marijuana, not to mention deciding if a religion is "right" or not. Can anyone actually KNOW they are right on any of these subjects? I contend that they can't really.