It doesn't seem odd to me, Valve already has a business relationship with Nintendo, publishing games on their console. They checked with their business partner

It doesn't seem odd to me, Valve already has a business relationship with Nintendo, publishing games on their console. They checked with their business partner before doing something the partner might not like. Even leaving off the DMCA legal stuff, that seems reasonable, and I don't think the DMCA case is as air tight as the Dolphin folks want to believe.