Half the time it would just be a Sysco product list.

Why would they? It's takes work with no return. It's giving something of value (theoretically) for nothing in return, not even good relations for the restaurant since they are now gone.

I worked at a pizza place that shut down, and it never even occurred to anyone. For one thing the owner was obviously stressed out worrying about a bunch of other things, both in the restaurant and in her personal life, and you'd be surprised how much of the food you get at restaurants is really just purchased from a company like Cisco and warmed up for you. We did make the actual pizza from scratch though, and that place had the best crust of any pizza place I've ever been too. The problem there was that the recipe was very simple. Just flour, water, oil, salt, sugar, and yeast. That's it. The trick is the exact ratio, and a proper pizza oven. The oven a recipe can't help with, and for reasons I don't understand scaling down recipes, especially in baking, does not produce the same result. A recipe that starts with a 50 pound bag of flour is useless to you, and if you just try to divide all the weights by 100 the end result just isn't good. All you really know is that you can make good pizza dough with flour, water, oil, salt, sugar, and yeast. That is not exactly shocking news.

Nobody is really thinking about it, with all the other things there are to think about.

Also, restaurant-style recipes aren't that unique, any chef worth his salt should be able to come up with something similar. Unless its something really weird, and worth keeping as a trade secret.

Then you don't tell anyone though.

restaurant food is basically normal food with a metric fuckton of butter, sugar, and salt added

How much demand is there for recipes from shut down restaurants? Unless the restaurant had a food that was well known and very popular, the recipes wouldn't be something that most people would seek out anyway. Even the popular recipes may not be worth publishing as they may take special equipment or access to a supplier that the general public doesn't have.

Because they're busy going out of business, I'd imagine. It's actually a pretty complicated process if you want to avoid a bunch of extra problems down the line. If publishing the recipes helped avoid some of those problems, they might do it. But they're more likely trying to protect themselves from creditors and get their taxes sorted and final paychecks and selling inventory and equipment and real estate...

Maybe they're preserving the option to try again with a new restaurant?

Besides all the other reasons listed. The value of a restaurant is that they feed you with an unique experience. The recipe is not the experience, it's just a broad guideline. Everyone knows how burgers are made. But I've tasted some pretty unique burgers in my life, for which the experience of having eaten would not be possible to replicate even if you had a gram by gram breakdown of the constituent chemicals.

Restaurant/chefs do sell menus to other restaurants/bars/chefs, so they may sell that off, but the public would never know about it.

I bet it's also common/planned that they would just reopen another one somewhere else. Esp if it closed for bankruptcy, etc.

Depending on the restaurant and the bankruptcy proceedings, the recipes may be considered an asset that can be sold to recoup losses. Those assets only have value when they are secret.

In one case in my area, the recipes for their signature dishes died with the family matriarch. :(

Maybe the recipes just weren't that good, which might have something to do with the restaurant closing.

My favorite Chinese place closed and I'll never taste that delicious sauce again...

Because there is no incentive when the only general goal in life is profit.

Accountability I bet