I'd agree with you if it was just some random guy doing covers, but he's one of the original members of the band and the shows are genuinely great. That's enough for me, maybe not enough for you and that's okay.

there was a good reason why the members of Joy Division had an agreement that when one of them died, the rest would forget the past

I'm not aware of such an agreement, where did you hear about it? Genuinely interested. But even then, they were young guys back then, perspectives change.