That argument is actually the same error that GP criticizes: Wavelength (i.e. quantized energy) matters a lot.

Being irradiated by hundreds of watts of direct sunlight is fine for a short while (and causes skin cancer in the long term!), hundreds of watts of microwave radiation for the same duration is already pretty bad, and the only good thing about hundreds of watts of hard gamma radiation is that you don't have to worry about the long-term effects too much.