I agree. Without this post, if I visited the page without any prior knowledge, I'd have no idea what this is about, and would have no incentive to sign up.
Maybe some sort of "guest mode" where you could use the site, pick a deck and preview the printing (maybe a very small image), but then required an account to not lose the deck or actually getting the printable would be pretty reasonable.
That said, maybe there's some other advantage to having an account that I just didn't think of.