The fact that you brag about it so boastfully is atrocious to be honest.
I didn't find his post to be bragging 'boastfully' at all. It reads chiefly informative and at times positively surprised. He found a technique that seems to work pretty well and he informs us about it.
I think your opinion is too harsh. Imagine yourself to be the customer of this website. You come across something you like so much you're willing to pay for it and you make the commitment to actually do so. Sure the revelation that the product does not exist yet is disappointing, but he also didn't take your money yet, and his website already convinced you that the product is going to be what you're looking for.
The shady part is doing the pivot without doing another opt-in. It's a classic bait ("Subscribe to get access to videos") and switch ("Continue paying to get access to a community and the promise of plans to make said videos in the future").
There's a major difference between trying to scam someone and pushing the boundaries to validate (and de-risk) an idea. If our ideas are shit, I will never take someone's money for that (hence the no questions asked, full refund).
These are Hacker News commenters, prototypal white knights eager to show off their perfect moral compasses, disregarding any opportunity for reflection or relativism.
No, it is not something I would have done, but I really understand the need to have some idea of what's going to work, and could see how one might go too far in pursuit of that.
For someone who is hearing of you for the first time, combining the subject matter under discussion and your admission of obviously exaggerating your post title makes you come across to me like a habitually deceptive person IMHO
For every person that has criticized this, I have had another one saying this is great. I also know for a fact that I'm not the first startup entrepreneur to do this.
I have already apologized to each and every one of our customers. I have also mended the relationships (AFAIK) to the extent that the "angry" customers would consider being customers in future.
Ultimately, I think that this was ballsy publishing this and being open about the pro's & cons of this. I'm not saying that this is the best technique ever and neither am I saying that everyone should follow this approach. I am however saying that it worked for us and I am keen to engage others on this topic.