The power button is the most useful part on a computer as it can fix (and also cause without user knowledge) many issues that you come across each day saving you from putting is a call to your IT department or a drive to your local repair shop.
Your laptop ends up on a news site at 1:00 AM that has a loud audio track, just push the power button before it wakes up your spouse. Your computer downloaded the coolest virus from the Internet and you don’t want to share it just yet with your Intranet, just push the power button. It’s 5 minutes to closing at your job and the computer is doing updates, just push the power button.
As you can see above, the power button is a quick fix in a situation but in doing so, creates an improper shutdown which will corrupt the data and OS on your hard drive.