Now, I have raised this on Google Plus with @tbfleming, I have emailed, I see other people have emailed, and I do have sympathy for the author in saying DXFs are a mess.
I do agree it is, but I also do believe that whats standing in the way op opensource CNC the most, is the belief that we can adapt the world to us, instead of the other way around. For many of us to suppport a project, we need to use a project to make money. Reprap got it rights years ago, it creates cashflow for the developers.
This here is the same, we have a army of open source machine owners who can make money out of their garage and in turn plow some it back to the author or other projects
BUT, and thats a big one, most of your 'customers' have Never used Inkcape. CAD has for years been dominated by DXF as the lowest common denominator between CAD/CAD and CAD/CAM. If I want a part made, I send a DXF to the factory and pickup tomorrow. Simple - no questions about dimension or pixels per unit or none of those crap.
Blaming DXF files with disconnected entities is to me a easy way out - and I am not happy with that. We have developers with skills.... The reprap slicer guys have long figured out how to repair STLs on the fly - and thats in 3D, with DXF we have on less dimension so it cant be that hard! We have talented developers like @andrewhodel etc who also has a grasp of this....
Heres what I am thinking:
a) We are looking at the DXF at too high a resolution - most commercial packages just assume if the endpoints are withing 0.1mm of each other they are connected?
b) Adding pre process instructions like "Save as R14 in QCad before opening in JSCut" is completely acceptable
c) TALK about it. Dont just wipe it under the rug as Impossible! We know its not!