The problem with this article is your idea isn't completely validated until people are paying for it (or just using it if your goal isn't to make a business of it). Going out and talking to people is great, getting them to commit dollars to get you to build it, even better. But the whole reason MVP exists is to get the validation that your idea is on the right track. It doesn't have to be perfect, but you get the feedback which will help shape the idea. Of course, the danger here is that the feedback becomes the form of 'it will be successful if I can just add x feature'.