I hate your stupid t-shirt

Whoever originated the saying "When you 'assume', you make an ass out of 'you' and 'me'" is an idiot and a loser, not to mention a douche bag for trying so hard to be clever that in the process they created a fallacy that has set society back 60 years.
People are clearly afraid to assume these days. I'm not! If I'm walking down a dark alley and I see a figure emerge from the shadows, brandishing a gun and wearing a ski mask, I am in fact going to ASSUME that they have some sort of ill-intent, presumably towards me. The only problem we've encountered isn't with assuming but with common sense. I could also, in an attempt to be politically correct, assume that the individual previously mentioned has legitimate reasons for the situation and approach them to find out…
Indecision has become our default, and rather than act or take charge, passing the problem along has become a typical solution.
Always ASSUME a gun is loaded, always ASSUME the other guy will screw you over, and always ASSUME the worst. Is it such an asinine concept to think that we actually have the ability to accurately reason and make assumptions that will benefit us? There are plenty of individuals who I would never give this credit to; I would like to think that most of us do possess this ability to some degree however.
Do I stereotype? Hell yes! Do I assume if you're black you are a rapper or that if you're Jewish, you are a jeweler? Not at all. (I assume that if you're black you don't tip well and that if you're Jewish, I should probably have some alternative food choices when I invite you over for the pig roast.{this is a joke}) For some reason, the promulgation of a politically correct, de-masculinized society that is overly concerned with everyone's "feelings" being my assumption, we have begun to cower in the face of decision and choice. What if I choose wrong? What if I offend someone? What will people think of me?
We lack conviction and strength. We lack the courage to stand up against anything except standing up! Apathy has been the precursor to nothing, ever, and never will be. The great wars that have shaped this world and the tragedies that have defined it, started and ended with individuals that had the courage to stand up.
The apexes of history have never been based on certainty and it's a pusillanimous person that needs such reinforcement to make a decision or take action.