It's clear and well documented that a person's success is heavily dependent on mindset, outlook and attitude.   Of course, circumstances are a factor - things beyond your control will always play a part. However, if you are have a negative outlook and always see the worst, then progression (not just promotions, but through life) will be stunted.  

My feeling though, is surely it perpetuates things when we focus on the negative behaviours that unsuccessful people exhibit.  Surely we should be focusing on the positive behaviours that successful people exhibit?   Rather than saying "don't make excuses" or "stop lecturing others" let's say "be accountable" or "practice what you preach"!