You're letting MS of the hook too lightly, in my opinion.
If Windows was -> OEM license: Regular licenses :: CVS : Costco (All OEM does is give bulk discounts), you'd be right.
If most OEMs weren't abusing their position by packaging cruft with Windows, you'd be right.
But when a company imposes T&C, often specifying exactly what apps/programs goes where, and doesn't insist on removing cruft, their silence is deafening.
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By the way, I'd blame MS the same way when OEMs sell underperfoming computers with Windows (um um, Vista). It's true that Vista on a behemoth machine for its day was quite usable, but there's no excuse, when you're already dictating resellers policies, for letting them put windows on a 512MB of RAM machine.
I'll admit it's the OEM's fault also, but Microsoft gets part of the blaim
I wasn't trying to blame MS, only referencing that this kind of situation had already happened in the computer industry.
I think they knew what they were doing. They didn't clamp down because that would have kept prices higher and hurt sales, just like your example of dictating a minimum amount of RAM that's too low to be actually usable. They could have gone higher but must have figured the extra $$$ would be better than the $ lost due to reputation issues.
Once MS puts their foot down over not selling OS/2, they better include clauses that protect the customer.