I am interested what their plan for the DX form factor is. I really don't like the small form factor of regular kindles.
So I think it will be an expensive second-class citizen for the forseeable future. It's not in their interest to change that.
I suppose you mean "make no money", assuming PDFs are off-the-net stuff, which is quite likely.
A couple of years ago I got a Kindle DX for technical PDFs, and haven't used it much past the first year - it's not really pleasant to use. It combines the size/weight disadvantage of an iPad 10" (not the upcoming mini ;-) with the slowness and poor resizing of eInk.
http://www.theverge.com/2012/9/6/3298468/amazon-kindle-dx-ki...