I can definitely imagine a certain number of somewhat over-moneyed techies who played/play shooter video games are gonna wanna go there for the nostalgic flashbacks to the time they straight-up headshotted somebody from the top of the creepy-ass rusted-out ferris wheel in Pripyat.
Weird story. I was in Chernobyl last summer on a guided tour, and it didn't feel very underground at all. Companies sent foreign visitors there to experience a little local flavor. One hungover guy was constantly reminded not to sit on the radioactive ground. We even stayed in the zone for the night, in Hotel Chernobyl, one of the radioactive zone's two hotels.
There are probably some tours that don't follow a laid out government safety guidelines for visitors/tour operators.