"if Apple can spend $60 million putting an iPad trademark dispute to rest, then why wouldn’t Microsoft spend what it needs to keep the brand that’s heralding the new area of desktop and mobile application development on their flagship platforms."

Maybe because there's a difference between a small Chinese company fighting to stay solvent and a multi-billion dollar retail entity with a presence in much of Europe and Asia?

Add to it that the Metro group is not some competitor nor an unrelated business, but a major retailer that sells and will continue to sell windows PCs. It doesn't look like a dispute microsoft would want to win just for a cool name it didn't bother to legaly check first.