the big issue with DIYs, is what does the future hold for such craft.
It would not be inconceivable that at some point the FAA requires them to be inspected for air worthiness. Not even sure that is not a bad idea.
Currently you can still register them but with the FAA who knows what future regulations hold in store
Even the "consumer" rigs on the market will experience the same issues with government certifications. To the best of my knowledge DJI is the only consumer market company performing certification work and most all of that is based around tracking technology for them to promote to regulators for incorporation into the regulatory process. Large aerospace companies started sending their new component design to the ASME for certification testing a couple years ago but at our level I don't know of anyone doing so. Perhaps Intel with their Falcon system and a few others at the very high end level but certainly nobody that's importing drones from China for sales in the general drone market.
It may well turn out that a DIY builder might end up ahead of the game. As the ASME (which has already been designated by our FAA as a "Pathfinder" and approved testing agency for certification purposes) completes individual component tests and provides approvals the DIY builder could pick and choose from the certified and approved lists to incorporate those components into their builds. Those mass producing complete systems would have to submit complete systems for certification testing, which most will not do because of the cost involved.
One thing is absolutely certain; as "certifications" become a mandate our costs will rise exponentially, driving most of those currently operating out of the commercial market because they will not be able to afford the equipment, or have the time and personnel to keep up with other requirements. What will happen is those looking to make money operating drones will have to extremely well financed, and heavily staffed in areas of maintenance, training, safety and system improvement before entering the commercial market. I hate to say it again, but as long as we remain divided as a group there is little or nothing we can do about the shape of things to come.