There is no global option for that in front-end. But if you upload a product with the catalog and search visibility then every product will get that settings. For change the visibility you have to change it from product->edit->option. There is no way rather than this.
What Aaron is saying is his catalog is set to hide out of stock items. But when creating a new product in the sellers dashboard. The item resets to “out of stock” regardless of which inventory options you tick, or dont tick, and there is no other way to change the stock level to be “in stock” other than to do this from the backend admin area.