Oh, and by the way, a very good article, highly recommended: http://www.investopedia.com/terms/r/returnoninvestment.asp
In other words, you don't make a ROI in much the same way that you don't make GH/s. ROI is a performance measurement. Now I'm done with the topic of ROI
Look everybody knows this formula already, but your conclusion makes no sense whatsoever. You can absolutely make a Return on your Investment, saying that's incorrect because there's a formula behind those words is just silly. When people talk about 'making or achieving ROI' they obviously mean positive ROI as negative or 0 ROI is not a 'Return on your Investment'. Get this simple fact through your head please, I'm sure you're smart enough to understand it.