And this isn't a problem of "testing them all". It's not like there's 4 rogue configurations floating around in the Windows ecosystem. It's TENS of THOUSANDS of people, and the problem falls well within what should be standard pre-release testing.
And I think people would be far less upset if it weren't for the fact that Apple tries to pretend it doesn't do things like install bloatware.
Also, your "TENS of THOUSANDS" of people are a frigging drop in the bucket compared to the TENS of MILLIONS (or possibly even HUNDREDS) of Windows systems currently in deployment in countries where Apple distributes their products.
Don't people constantly defend Microsoft with the same argument -- namely, that they have no way to test every possible interaction between bad drivers and hardware components simply due to the sheer number and variety of Windows systems in use at any given time?
The issue presented here isn't microsoft, its Apple. its about apple's iTunes product being sub-standard quality. And thats that.
And tens of thousands of users having the same problem (and having it be reducible in 2 or 3 days to a repeatable problem) means that there was little to no testing done. Part of testing is USING the myriad environments of the ecosphere in which your application will exist. It would be like writing a web phone app that only works at 120 x 160 but crashes at 128x128. Sure, it doesn't crash on EVERY phone, but it crashes on a significant number of them.
(It's unclear to me, by the way, that your claim that only a few systems crash is true. I'm able to reproduce the error bug by doing a clean install of iTunes 8. It seems like the problem is much larger than you want it to be. But even if I concede your point that it's smaller than everyone, it's still large enough that we're seeing 'software malpractice')
And Microsoft got hip to how bad the "but there's lots of systems, wahhhhh" excuse is. Welcome to the 21st century. Apple should get hip to how lame that excuse is, too.
And I'd like to point out the fact that nobody notices if something isn't in a EULA or License Agreement until there's some really horrendous bug (like causing a BSOD) and people start looking in them precisely so they can say the terms aren't there. I mean, what do you want, a checkbox that says "Do not install drivers required for the proper functioning of iTunes"?
Le Sigh
Why then should it be surprising to anyone that it installs background processes and drivers? Yes, malware authors use hidden background tasks, but so does everyone else. The technique itself is not evil.
Furthermore, blaming Apple for poor QA because some Windows systems crash when iTunes 8 is installed is ridiculous. Windows is an ecosystem, not an operating system, and there are far too many possible system configurations for Apple (or any other vendor) to test them all.
There are plenty of causes to call Apple evil (DRM, restrictive platform access, insane RAM pricing) or incompetent (MobileMe launch, iPhone 3G signal issues) but a buggy Windows experience isn't one of them.