It's a business, not a charity. They brew what sells.
+1. That’s one reason why we brew our own: so we can get what we like that we can’t find (aka doesn’t sell so very few brew it).
In addition, the primary reason we brew is to ensure that we have fresh beer available. And the beer we want to consume, not the watered down light beer that the legacy breweries want us to purchase.
As my palette leans towards Euro-Lagers, it is not easy to get a 1/2 bbl keg that is fresh, or will remain fresh until the keg is emptied.
So we brew our Munich Helles is 10 gallon batches, and the beer will remain fresh in taste until the keg is finished.
My last keg of Hofbrau Munich Helles did go bad, near the end of the keg.
I have had Budweiser and Sam Adams beer go bad while in the keg.