Base load generators cant adjust their output quickly enough to match the daily demand curve. Your options are to keep them online at a fixed level 24/7, or cut them entirely. If you don’t have enough renewable production to meet overnight demand, you have to meet that demand with base load generators, which means you have to keep those generators online. If you have to keep them online, and wind is providing more power than is being demanded, you have to cut the wind production to match demand.

To get those (usually coal-fired) generators offline, you need to drop your overnight consumption, add storage, switch to non-fossil baseload generators (nuclear), use less efficient “peaker” plants (usually gas turbine generators fired by natural gas or oil), or some combination thereof.

You’re right, it is “fucking stupid”, but it is due to the functional limitations of the equipment they currently have available. With those limitations, the best option is to export your excess wind production to someone who needs it, and improve your own grid to reduce reliance on fossil fuels.