We don't mind changing our habits if it's for some greater good--say productivity, longer battery life, or whatever. But forcing everyone to change their ways for the sake of one person's preference is obnoxious. That's how we see changes to the Green Button, one-third of the red-yellow-green window-control trio also known as the Stoplight. In versions prior to Yosemite, pressing this button would automatically resize the window to fit its contents. The control for going to full-screen mode was the double-arrow button in the top-right corner. In Yosemite, the double-arrow (and its full-screen function) is moved to the Green Button, whose auto-sizing function is relegated to an option-click double-clicking the title bar (which previously would hide it).