This may be true for games (I'm not sure), but I'm not sure it's good advice for startups in general (in case anyone was thinking that.) Throw things at the wall and see what sticks. Don't fall victim to sunk cost fallacy.
You have a point. But today's world quality and polish matters a lot. Point is before you judge make sure you provided good quality and a polished product. The idea matters a lot but if you don't present it well its good for nothing.