You have the absolute dumbest takes on this issue. Having a BO Barb in the group means it is not hardcore? Does that also count for having a druid with Oak Sage? How about someone with an infinity merc? Wait, so people have to be helping with the kills for it to be hardcore or should everyone else sit in town while one person kills sans BO for it to be hardcore? The only hardcore players are people who play by themselves witout BO or is a CTA ok? Or is that "light" hardcore?
Do you even remotely see how gobsmackingly stupid it is to suggest that someone killing everything themselves with the benefit of a BO barb is somehow "not hardcore" but running with a group of players that contains a BO barb and who are also helping with the run somehow is?
If it was actually just playing with another real player using a BO barb I don’t think people would be so prickly about it, imo it’s different if it’s multiboxing. Hacking the game to give yourself 3x health and mana would be hardcore lite, multiboxing a BO barb is functionally the same thing with extra steps.
There will always be people who’ll think the way you play is wrong regardless of what you’re doing though, it’s just a game and you should play it how you want. I personally don’t see it as any different than people that play with single player QoL mods, live your life and play the game the way that’s most fun for you.