A comparison of someone with a successful track record due to his having a mental "backbone", as opposed to a cowardly weakling who is reluctant to speak up or try anything new/risky/unconventional because he fears failure and/or offending someone, and so he lives a life of stagnation, shame, and mediocrity.
To determine which side of the "winner vs. wiener" scale you are, consider whether or not you're willing to "go out on a limb" for the potential betterment of your life, take an unpopular view in the interests of morals or progress, or to step out of the crowd and stick up for someone else.