Yes, I am officially affiliated with GOTD. Both Lee and I are volunteer moderators who are in contact the the site owners and web team in the event of issues or to pass on feedback from users. We also moderate these forums and provide assistance where possible.
Am I guessing there haven't been any changes? Occasionally in the past I ran a sniffer to check what valid traffic (to and from) looked like. I haven't looked at it over the past two months. So, I could be guessing. But logic would dictate that if it worked before it should continue to function. Assuming the activation program can actually communicate cleanly with the GOTD server there is no reason why it might work one day and not the next.
If the Activation suddenly stopped for all GOTD users, then I would say the problem is probably with the activation servers or program. But when it is only the odd user here or there (except for a group of users with a Singapore ISP) for whom the activate fails, it would indicate the problem lies either with the end-user or somewhere along the path to or from GOTD.
As for users thinking that GOTD is simply a bogus site - this may be the case, and all the discussions about favorite software, or like/dislike giveaways, and reports discussing the great programs that have been given away over the last year, is probably just GOTD inventing "posts" and "imaginary blogs" to trick people to download shareware. (No, you're right... that idea is just a bit too silly to believe).
My aim in posting earlier, was because I have a lack of information on why certain users (in the minority) have issues activating software. If I can get more information, I might be able to see a pattern or possible common cause - and perhaps make a suggestion to the GOTD team on how the activation process could be changed - or the problems detected with better error messages or diagnostics given to the end user - so the problem can be resolved.