@Bas:

I am not sure what you mean. I can easily tell which is the top side from the bottom side of the micro USB. I can even feel it if I want to. I have never failed to plug it on first attempt.

Not saying you have bad eyes or can't feel it with your fingers, my mom did the zombie way until she broke her phone. So, I can understand what you are coming from.

The manufacture can easily add blind man's dot text on the rubber side of the plug. And have different color on the top side. Both are very easy to achieve instead of relying the two dumps on the metal part.