At the forum were I gave the link one user explained why he was confused:
There are 4 screenshots on that particular theme page, so the brain just didn't mark it as the same single link. He clicked on the linked theme name first, it just reloaded the page. Wondering why is it there, he noted the 'Zip content' section and scrolled under it looking for 'Download'. The shots were the last choice.
Other users agreed with that note. There are all sorts of buttons there, except for a very natural 'Download'. And it's very easy to add it to the template, I think.