24.99 a person is what's in it for Apple. This could be just me, but Match has also made me purchase more music from iTunes just to add more to my library without the hassle of it being matched.
The paranoid conspiracy part of me almost makes me believe that this is not accidental.
I've had more than a handful of albums where only one song is not matched - completely random, from what I can tell.
I disagree. The files you download from Apple are DRM free. Therefore it doesn't tie you into the ecosystem at all...
I actually beieve that they do want to keep you in the ecosystem. Not on the OS side since they do support Windows users, but on the mobile side. No Android version, for example, means that you'd need an iPhone/iPod Touch/iPad to make the best use of the mobile capabilities of iTunes Match.
As for the OP's original question, that one I can't answer. Why didn't they just do what Amazon and Google are doing, which is just allowing files to be uploaded as is? Or match with a better version, but NOT allow it to be downloaded? Maybe they felt that there are a significant number of people with older 128kps files of the CD rips, their legit eMusic files or that "questionable" stuff and that the Match / download offering would snatch a large number of these people from Amazon and Google.