Promoting based on longevity only in a business where performance is easily quantifiable seems like a poor decision. Any sort of promising "rising star" you have is going to quickly become frustrated and find a better job when he gets passed over for a promotion solely because Mabel has worked here longer than he has.
Anyone who thinks that he's entitled to a promotion before someone who has worked at a company for far longer than him isn't the kind of person I want working for me.
But the real point is that your mentality is based around the idea that you have bad or mediocre employees continuing to work for you. Sorry, but that's the real bad business. First,
you failed in hiring a poor or mediocre employee to start with. That means that you need to reevaluate your hiring process. Second,
you failed in continuing to allow that poor or mediocre employee to continue working for you after
you failed in hiring them. Third,
you failed in motivating the employee to work harder, probably because
you have a poor work environment based around the idea that people should be stepping all over each other trying to beat each other to promotions or raises because it's a competitive environment in a zero-sum game.
Old school ideas around how to run a business and deal with employees need to die. We've seen time and again that when progressive ideas are tried, they succeed in droves. Take a look at the new concept of unlimited vacation time that several tech companies are now using. Traditional business scumbags like Jack Welch raised holy hell when this came about, claiming that employees can't be trusted, and that they'll abuse any leeway you give them. The actual result? The employees at these companies are using
less vacation time.
Throw out what you've been told. Sticking to the old way of doing things is the real path to mediocrity.
