The figure itself is derived from the statistic you provided, the only speculation is my belief that the percentage has probably since gone up. I don't think that's an unreasonable assumption, but it doesn't matter.
I don't know what you mean by me not being knowledgeable about how things work in the video game industry. None of the games I've purchased and played recently had any unplayable end-game content. Even Paradox Interactive, known for buggy games that don't work initially, usually patch up their games after a few days. But even then, this is Blizzard and that's an indie company with a niche fanbase. They were testing Starcraft II months before releasing it and patched it many, many times during the beta. There's really no excuse for them, they should have had the resources to make Inferno playable (I'm not saying perfect, mind you) but they chose to release the game unfinished instead.
While some of these complaints might be a overboard, I wouldn't want it any other way. If this shows Blizzard and other companies that they can't just release a half-finished product and make millions off of it, then I don't care how many threads about "D3 sucks" I have to see on every forum. I do not want Blizzard to set a precedent here.
I can sit here and point out games that have been released that did have unplayable end game content but that not the point here (I'll point out one, WoW). I'm pretty sure Diablo 3 closed beta started last year in the end of summer, seems like months of testing and patching to me. Inferno I would defintly say is in fact playable, if people have progressed up to Act IV then its not fair to say it isn't playable. What I thought you meant by unplayable was unfairly balanced to be a heavy gear check rather then skill check. If this is the case, then it seems like a legitimate problem at launch to me, which will take under a month to provide a solution for.
What your not understanding is this isn't showing blizzard anything other than they have a portion of there players who are impatient, jump to conclusions, and choose to make worthless "D3 Sucks" threads. Like I said before, most the people are enjoying the game, the minority just happens to be the loudest.
@ KingSaber, What exactly makes Diablo 3 unpolished other than the fact that inferno is apparently "unplayable". I haven't encountered a single bug or game breaking experience and I would say I've progressed a lot. Seems pretty polished to me. I feel most people who are bashing D3 right now is because it simply isn't D2.