Actually the quote "the plural of anecdote is not evidence" is illogical and sets up a false premise. When several people report that something specific and repeatable works for them (assuming the placebo effect does not apply, which is a nonissue in this case), those reports cease to be "anecdotal" and become, in fact, evidence. Perhaps not proof, but certainly evidence.
I fully agree that ultimately Apple needs to fix this. That goes without saying. But that doesn't negate any solutions, workarounds (call them what you want) that help people achieve the desired result. If it doesn't work for you, because you're on Windows, I'm sorry about that. Truly. But you don't have to be an *** and rain on everyone else's parade like a spoiled child.
I'm not your average user who's susceptible to the fallacy of believing that two events that occur coincidentally constitute causality. I'm not that guy. I'm a power user who gets calls from friends and family to fix their Mac and iOS issues. I'm not perfect, but I pay attention to detail. Regardless, like most, this issue had me stumped. And yes, I repeat: The real fix should come from Apple. But until that happens, tips and workaround are viable and are helpful.
So, after trying absolutely EVERYTHING that was suggested, all over the web, and after iTunes Match was stuck for 4 WHOLE DAYS, despite turning iTunes Match off and back on at least 15-20 times (and probably more), I finally tried Nico's tip: I restarted the Mac in safe mode, fired up iTunes, and the very first time I selected "Update iTunes Match," it WORKED.
Will it work for every, single user? Probably not. But is it likely to work for some? Yes. Perhaps even most. At what cost? A simple restart. For any user (on a Mac), it certainly won't hurt to try.
If it doesn't work for Windows users, I feel your pain. But attacking me for exclaiming that I found a solution that DOES work — at least for some of us — doesn't accomplish anything except making you look bad. There friendlier, more constructive, and more accurate ways to get your point across.