The main reason I could think of is when you consider the reality of our electric grid and how it remains stable.

Grid inertia is literally maintained by hundreds of thousands of pounds of metal spinning at 50 or 60 hz.

So as the grid moves towards solar and wind, it loses inertia. Solar has no inertia and wind is lightweight compared to baseload plants.

This makes the grid more sensitive to another that can cause the frequency to fall or rise, which will trigger automatic protections.

It takes longer to become an issue in large interconnected grids, but on islands it's like the leading cause of blackouts.

One badly timed cloud means problem, unless you can instantly replace the energy lost through other means.

With thermal power plants the inertia of the generator spinning gave utilities enough time to start up other generators. With solar and wind that's gone, hence the rise of grid batteries.

So then solar/wind costs should include ALL related costs, including grid batteries and such, and often it doesn't. And thus you get people who are against it for honestly a very good reason.

That said I love solar and run fully off grid, but I ain't deluded to think my island can go 100% green. Diesel will stay for now.

I do wonder if using solar to run huge heavy flywheels connected to generators can help with the interia issue.