"they would produce vast amounts of energy with little radioactive waste, forming little or no plutonium byproducts that could be used for nuclear weapons."
Fusion products are helium, neutrons, and neutrinos. Stars eventually fuse products up to iron.
To generate plutonium requires a supernova...
Do you think it's perhaps possible that the author knows what he's talking about? If you'd continued reading after that second sentence you might have come across:
> In fact, these neutron streams lead directly to four regrettable problems with nuclear energy: radiation damage to structures; radioactive waste; the need for biological shielding; and the potential for the production of weapons-grade plutonium 239—thus adding to the threat of nuclear weapons proliferation, not lessening it, as fusion proponents would have it.
Also, the plutonium production is the bottleneck. E.g. this article about the Pakistan nuclear weapons program[0] estimated that the 50 MW nuclear reactor in Kushab could be used to produce 10kg of plutonium and 100g of tritium per year. The plutonium would be enough for about 2 bombs, while the tritium would be enough for 20.
[0] http://nuclearweaponarchive.org/Pakistan/PakArsenal.html
Or an energetic neutron source, which a fusion reactor provides.