So basically what you're saying is because Jimbo Wales is busy running things on the WMF board, then the userboxes should stay?
That's a pretty weak argument.
By your logic, if Jimbo can't write articles, why does he make us do them and then get in trouble with the press when controversial issues arise? If he can't do them himself, they should stay unwritten.
I think his argument, (and if it isn't, it's possibly a stronger argument), is that it's not up to certain un-named admins to delete userboxes on Jimbo's behalf, based only on their interpretation of Jimbo's statements on the issue, because if Jimbo really wanted userboxes to go he'd say so.