1000+ hours in VT2, 3000+ hours in DT. I ran into ONE person who tried to use scoreboard data to prove to others present in that match they were under-performing. He was laughed out the room. I ran into hundreds of cases where scoreboard data enlightened me about whatever my new build is doing what I expect it to do or whatever a specific talent or blessing proves itself worthy during an actual mission.
There is NOTHING toxic about scoreboard data itself. The only concern I would have is whatever mods like scoreboard influence client and servers performance, if at all. I say it without much knowledge about how scoreboard mods data is accumulated.
Could the official summary screen use some improvements, to entice players to do better, and feel them witnessed for whatever they have done well? Sure. Could match coop experience be a bit less transactional and actually encourage grouping up with the same people again. Absolutely.