I have to say I completely disagree with this request.
If code it too large for a 9000 character window, it deserves downloading into a decent editor.
The present size is, if anything, about 3k too big, IMO.
A lower limit might encourage posters to try to boil-down their problem to its minimum, rather than just dumping their obscure, badly formatted monstrosity, unedited onto the forum (though I'm not holding my breath)