@allenJo - I’ll stay out of this debate for awhile. I’ll just note that I think the ability to measure solar radiation is extremely useful for determining other things that are clearly related to the sun, like solar flares.
I’ve heard we’ve had some powerful solar flares, which are giant explosions in the sun, and that these in and of themselves could have some disastrous consequences for the inhabitants of planet Earth.
I’ve read that solar flares could mess up our GPS communications or affect our electrical grid or things like that. I believe that the solarimeter could function like a fire alarm which would allow us to know that such an event was taking place, and allow utilities to put emergency actions in place.