Injury and death happens in rock climbing even when tethered. Not often but it does happen, that's the nature of the sport and it's the same as BMX, skateboarding, motocross, any kind of racing.
It's also the same as just living - go look up Taiwan traffic deaths. There's so much more dangerous things happening here and wherever you live, it just seems silly to criticize someone for doing an extreme sport publicly.
There's like one injury per NFL game ffs...
It's an extreme sport and a thrilling thing to watch. The danger is exciting and makes his accomplishment all the more stunning. I think it's really cool that there are humans willing to push the limits of the human experience like this.