Any of you out there business owners or supervisors? Did you always have your employees' backs or throw them under the bus? WHY?

I NEVER threw my employees under the bus.  I always went to bat for them as well - even if they didn't deserve it.

I had an assistant manager once who constantly threw people under the bus, plus he had a bit of an ego problem.  He was always eager to show off to his superiors (bucking for a promotion?).  It only took a few weeks before everyone hated him.  Whenever you had to work with him he'd always find a way to make you feel inferior, or work was never satisfactory, and if anything wrong he was quick to place the blame away from himself. 

Technically, employers aren't obligated to do anything for the employees save to give them a paycheck and (as per OSHA) a safe working environment.  However, employers who go beyond this minimum obligation usually have happier and more productive employees (which in many cases can increase profits).
Any good boss knows that their employees are the backbone of their business.  You can have a great product or service, but if you have bad or disgruntled employees your company has a higher likelihood of failing.   Treat your employer's right and they'll (usually) be productive.   Treat them like crap and that's what you get back from them.  Unfortunately, many bosses are only concerned about the bottom line (what they're aught in college).  They think that the bes way to succeed is to treat their employees like cogs, not human beings.  Got a problem cog?  Simply replace it.  Bosses like this usually have high employee turnover within their company.  Then they have to hire new employees and train them ... which costs money which usually comes out of any profits.  Whereas a boss who treats their employees good, usually keeps their employees longer, which means no money needed to rehire someone else, which means that money can now be put back into the business to increase profits.  Shame they don't teach this stuff in college.