So what? Conventional baseload plants also have the trait of being much bigger, thus a single failure or maintenance shutdown is a significant grid event. You could talk about the relative distribution functions, or about the difference in the pattern and spectrum of fluctuations.

However, even under the current conditions, capacities are strained

Yes, but not as much as claimed by certain circles; see my Enron diary.

and construction of massive new grid capacities is already meeting stiff resistance.

This argument is overblown to the extent that it sounds like an excuse. (And now a tool; with Rösler seizing on the opportunity to call for the easing of environmental restrictions.) There are 20-year-delayed power line projects in Germany with no significant counter-protests. There is also the issue of excessive coal plant production assumptions in the forecasts of the grid operators.

_{*Lunatic*, n.
One whose delusions are out of fashion.}