Big Kim isn't dumb, she's a complete narcissist. Her narcissism rules her control issues, and narcs HATE to be outdone, outshone, or contradicted. There is no way in hell that Big Kim was going to stay away from that gig. She could have easily had someone like Moriah record the gig and then watched it later, but Big Kim had to make it all about her feeling "hurt," and we all know she wasn't hurt - she was outdone by Olivia/the kids who left her.
My dad's parents pulled this shit with my mom that Big Kim pulled with Olivia. As my grandparents were not religious, they pulled the "you're men