Perhaps it was inelegantly put by the original commenter, but I think the gist is that the product managers who lack some of the important product management sk

Perhaps it was inelegantly put by the original commenter, but I think the gist is that the product managers who lack some of the important product management skills around vision, ability to be customer facing, and effective and articulate communications tend to work more like project managers—effective acting as tactical managers within a product as opposed to strategic ones for the product. We can define and name the roles all sorts of things (project manager, product owner, product manager, product marketing manager), but what it boils to is for any complex product there is a need for the management of the product at a holistic level and a need for management of a product at a granular level.