When highlighting an item and pressing the stock button, if you set the stock to zero the item is set as inactive.
Since we now have the discontinued option, I think it should be changed to set items as discontinued rather than inactive.
On the other hand though, we have completely removed the code so it just leaves products active and showing them as out of stock.
Not sure which method is best for everyone, but don't think it should be settings items to inactive. An option for what to do may be best.