'Fraid I am going to disagree with the pull theory - all emergency switches that I have ever seen need you to push them to activate, never seen one that needs you to pull, with the noticeable exception of a train where you pulled the cord for an emergency (but there was a reason for pull rather than push)
I actually find the location of the button sensible and very easy to use especially as I never need to release the brake, only ever apply it - I have banged my hand a few times on the Landrover dashboard looking to put it on when parking it up
