I'm pretty weirded out by some "modern" teams where you have product managers spoon feed specifications to developers, and developers focusing on nothing but the code they need to write to do exactly as they've been told.
Product managers are in a weird place. They wear a ton of hats and do entirely different jobs based on where they work. They're often really valuable, but I have some trouble putting my finger on what makes a good one. If they're good at whatever it is they end up doing, that's good.