A 50% emission reduction is huge, especially in the context of being able to reuse most of our hydrocarbon-compatible infrastructure. Not everything needs to be on orders of magnitude to be worth doing.
I agree that nuclear power needs to be a larger part of the story. But the author should motivate that without relying on misleading categorizations.
The success is based on the cost and timescales available now, not based on the past 18 years (which is that solar and wind costs have fallen massively while nuclear still seems to offer high initial estimates with a good likelihood of massive cost overruns).
Gas is far better in terms of carbon dioxide, but arguably worse than coal when you factor in methane emissions.
The only real benefit of gas, IMO, is that it's easy to switch on and off quickly and has the low fixed-costs desirable for a peaker plant (unlike nuclear).
The main takeaway for me is that nuclear isn’t getting enough press time because the prevailing view is that renewables are so successful, which he is arguing is essentially propaganda not supported by the numbers.