I thought some were hanging on to the idea that the route itself was OK, and that visual separation was just added as an extra to the already OK vertical separation for the route. Because the flight paths were intersecting anytime two aircraft were on those two paths.
Maybe I should amend my comment to say that someone thought that the route was OK given the addition of visual separation? But I don't know if that was ever a condition of the route universally, just applied by the controllers as an extra? Along the lines of they believed that the route was tight, but safe, and if everybody flew it just right everything would be OK. 150 mph closing rate at right angles at 75' apart is fine, because it only crosses for a fraction of a second.
The thing that had been keeping this from happening before was that the space occupied by both paths was small and separated by time. The small overlapping vertical component meant that sometimes they'd be able to pass at the same time without colliding. My bet is that no pilot, going either way, using visual separation ever even saw the near misses that happened before this.
Visual separation, at night in the airport environment, used as a compensating control for a set of paths that intersect isn't a control at all. As a comparison, the complexity and training around the use of close parallel runways at ATL weren't done for the fun of it, and as far as I know those paths do not intersect. But with the helicopter traffic, they were given the equivalent of a pat on the back and a "good luck buddy, you won't be able to see it if it hits you, but it won't last long". I'm not suggesting that was the intent, but it was absolutely the effect. Butch and Sundance jumping off the cliff.
Media people seem to want this to be about one person's mistake. A pilot, or a mechanic, or a controller. Or some sort of staffing issue. Some kind of c theory. Or something that has to do with classes or types of people. There must be somebody to blame. Nobody in the press wants to hear that it happened because the routes were just wrong. I didn't think that extended to people that actually fly airplanes.