Philipp's answer is a good general purpose answer for debugging stockpiles. In this case however, I believe that none of the options mentioned in it are the problem. My belief comes from the final paragraph in your question.
There is only one dwarf which moves maple wheelbarrow back and forth, others just drink booze.
If a stockpile has any wheelbarrows assigned to it dwarves will only ever use those wheelbarrows to fill it. This works best for things like ore which is produced at a fairly slow average rate and is very heavy.
If this is indeed the case then to get all the other dwarves to help you need to set the maximum number of wheelbarrows for the stockpile to zero. You can do this from the building information exposed by the (q) command. (hit q move the cursor over the stockpile and then hit w until the max wheelbarrows number is 0)
I would guess that the other stockpile worked because there was no wheelbarrow to assign to it.