My beef with things like this is not with the concept, but the way it is used. 'Does our call center add value to our product?' is an entirely reasonable question. 'Value-add' as a noun is a big red flag for me, suggesting the speaker has a poor grasp of the underlying concept and/or is trying to overstate the significance of the issue to seem more important. I feel the same when someone uses 'dialog' as a verb.