That's quite a rant, and I for one can appreciate a good rant as well as the next guy! I feel you when you talk about the seeming contradiction in the regs, in that something that would arguably make experimental aviation safer (commercial help) is not allowed. However, as John Hickey put it so succinctly, it is not strictly about safety. If the FAA wanted to mandate safety in experimental aviation, it could do so quite easily- by simply outlawing it. The effect would be extreme safety, but that is not really what we are after here.
The reason that this is a victory for us is that the balance between safety and freedom has not been tilted too far to the side of safety. The idea that the original wording is somehow out of date is hogwash. The "51% Rule," like the Constitution and the Bible, is just as relevant now as when it was first written. It allows us today, as it did then, to build aircraft for our own "education and recreation" as a non-commercial endeavor, without conforming to the myriad and $$$ FAA regulations that are forced upon the manufacturers of aircraft.
Your assertion that commercial assistance was somehow "allowed" for the last 50 years also misses the point. It was never allowed, but in some cases it was overlooked, out of bureaucratic necessity. Just as your local police cannot and should not be out to stop and ticket everyone who drives 1 MPH over the speed limit, the FAA had and has bigger fish to fry than the small minority of homebuilders who skirted the intent of the regs to produce experimental- amateur built aircraft as a commercial endeavor.
However, human nature is to keep pushing the envelope, and companies like Epic and Two Weeks to Taxi did just that, pushing the letter and spirit of the law to the point where the FAA had no choice but to step in. Sure, the increasing size of the fleet had a lot to do with that, but if every one of the 30,000+ homebuilts in the FAA registry were legitimately built in 30,000+ garages by true homebuilders, this issue would not have been forced to the surface, and we would not be having this conversation now.