I agree, but there is a slight problem with the suggestion. That's the way it worked originally and there were problems that barrels never got filled :-) I can't remember what version this problem was introduced in, but it was a fix for the previous problem.
While I prefer stockpile before barrel, personally, this could be worked around if giving from a stockpile that allowed containers to a stockpile that didn't allow containers worked. At the moment it doesn't. So if you have a stockpile that allows barrels and you want to distribute the contents to a stockpile that doesn't allow barrels, nothing will happen until *all* of the barrels are full in the first stockpile. If that were fixed, you could have a general stockpile that allowed barrels and feeder stockpiles that only had 1 or 2 tiles and didn't allow barrels.
In the meantime, the work around is to never use barrels. It's not as horrible as it sounds as long as you aren't over producing plants. Also you can use barrels for *some* things. For example, if you have a plant that you *only* use for brewing, you can put it in a barrel no problem. Same for plants that you will only use for grinding in a quern or mill. Just set up a stockpile for that one thing and distribute it to the one worksation that needs it. You can always distribute from stockpile that doesn't allow barrels to one that does, so as long as your general stockpile doesn't allow barrels, you will be fine.
Normally, I make specific kitchens with linked stockpiles of specific ingredients. Those are my cooking ingredients and they can not be in barrels. As long as I make sure to use each plant for only one thing, that's the only thing that can't use barrels.