From our perspective outside a black hole, matter never quite passes through a black hole's event horizon.
True, but it does get farther and farther red-shifted, effectively disappearing.
And there will still be this event-horizon-sized region that is not emitting or transmitting light. I think that formed the basis for the luminosity comparison: neutron stars, with no event horizon, would have been brighter in the central region.
Slashdot Mirror
From our perspective outside a black hole, matter never quite passes through a black hole's event horizon. True, but it does get farther and farther red-shifted, effectively disappearing. And there will still be this event-horizon-sized region that is not emitting or transmitting light. I think that formed the basis for the luminosity comparison: neutron stars, with no event horizon, would have been brighter in the central region.