one of its European partners?
Surely the problem was that the German Metro brand owner was not a Microsoft partner in any form giving MS no leverage to bully and nothing that particular supermarket chain wants to bargain with.
Given that any online "Metro Store" would suffer feature creep (as seen over at Google store), killing a potential competitor would make sense to a retailer with no MS dependencies. What's wrong with Windows Modern though (or even "Windows Metro"), if they're allowed to bolt Windows and Mod together they'd have no more trouble doing Windows Modern and it's a hell of a lot more stylish. Even if the product it describes is the opposite of stylish ;)