I don't really understand the downvotes here, he speaks the truth. Every rule has exceptions, especially the "get 10 signed customers" rule. If you are passionate about the idea, then you should be confident and let it ride.
The issue as I see it is that not everyone has great vision when it comes to building products/services one could turn a business into. In fact most don't which is why the 10-will-you-buy test is a good way of hacking around this lack of vision.
The funny thing is that the blog's author himself succeeded without talking to customers. Imagine if he talked, found out nobody wants it and quit without pivoting.