They only make sense if there are shortages of real, full-function graphics cards. The point is that you are essentially buying yourself more time by not waiting for normal graphics cards to be in stock. The quicker you can throw hashrate at some coin out there, the better chance you have at meeting/exceeding your ROI while the difficulty is still low.What is the point of these "mining" cards anyway? As far as I can tell, all you get is a shorter warranty and limited resale options thanks to missing video outputs.