Orion have plenty of failure mode that are simply not acceptable. If there's any mechanical failures stopping the successive nuclear explosions over the world during launch you are left with a thousand pellets of radioactive material that will not stay contained on impact (not saying they will detonate).
Even if you could guarantee 100% safe launch, a nuclear pulse thruster is simply not practical, to be taken seriously the fanboys need to look beyond planting flags, nuking stuff & looking cool as their only criteria.
The nuclear Orion concept was only efficient at launching stuff (if nothing else mattered), it cannot be used for small jobs, it's not something you should mass-produce like Starship, it had no hope of becoming reusable on Earth, neither as a good lander, its peculiarity wouldn't make it a good tug ship or even something you want around others space installation because of space debris, justifying the crew aboard would become its only job.
Refueling/reequipping one/more would require so many new technologies -we still don't have- and fleet of chemical rockets that you would be better abandoning it far away once the warranty expire.
In the last 70years chemical rockets launched thousands of comm satellites, probes, we did decades of constant scientific research on the ISS sending new sensors/experiments as fast as we developed them while learning how to make human able to live in space, learning how to maintain old space equipments.
The best you could imagine one/fleet nuclear-Orion do is plant a flag and get us minerals back from a planet where human exploration isn't suicidal while competing with its own automated probes. Maybe we would have got an emotional human moment if a reckless missions led to the death of the (superfluous) crew.
I do want nuclear propulsion in space, but I want real shit done and a nuclear-pulse Orion is simply not interesting.