Photoshop CS6: Why is 'Maintain Aspect Ratio', in Free Transform mode, unselected, by default?

In Photoshop CS6, if using Free Transform to change the size of a newly-made selection, you have to click 'Maintain Aspect Ratio' option every time to maintain the aspect ratio. How annoying is that! Why isn't this 'Maintain Aspect Ratio' option selected by default? Certainly in my case, there are vastly more occasions when I want to maintain the aspect ratio, and so, in my case at least, it would be much more user-friendly to have 'Maintain Aspect Ratio' selected, by default. Or, alternatively, why isn't there an option in Preferences to either have 'Maintain Aspect Ratio' automatically selected, or unselected, by default, leaving the user to toggle from this starting position, if they want? I know you can hold 'Shift' while resizing, but for the vast majority of the time, I would like to maintain aspect ratio and it would be helpful to have either this option selected by default, or have control in Preferences for the default setting.