To use a caricature, homebuilders are probably very similar to people who rebuild E-Type Jags etc from a pile of rusty bits of metal. Nothing wrong with that; they are just not your average PPL.
Ummmm, I actually don’t know that many people who aren’t like that, private pilots or otherwise. Its a personal problem 
Maybe a few of my motorcycling friends might fit the ‘vehicle user/consumer’ mold, otherwise nobody except family – who aren’t pilots. The rest, including pilot friends worldwide, are all gear heads. Some of them have other attributes too and I manage to lead a fairly normal life despite this handicap.
I am severely handicapped!
But the problem is – where do you draw the line? A C172 can be – and many are – used for commercial ops, sightseeing, meat bombing, survey, etc, etc. People do sightseeing flights, or ‘experience flights’ in C152s. The line isn’t as clear as ‘C172 vs A380’. There are many, many shades of grey in between.
There is no well defined line, I agree, but we have the same “problem” in commercial vs private pilot license. Most cases are obvious though. Sightseeing flights are clearly commercial if more money comes in than goes out, and even if no profit is made it is commercial in my opinion. “Experience flights” are more difficult because it is not very well defined and is dependent on circumstances. In some cases it may end up in seemingly ridiculous situations, like farmers cannot legally use their microlight or experimental homebuilt helicopter to look for their sheep in their woods and mountains, but this and similar exceptions should be easy to handle. Trying to “commercialize” GA flying, mix commercial and recreational/private flying, in the hope that it will somehow ease the economical burden will have the exact opposite effect for everybody. The exception is high end flying in business jets and similar, there it is irrelevant. In my opinion there is only one way to lower the economical burden, and that is to substantially ease the bureaucracy and focus on the recreational part (including sporting activities).
Regarding the nonsensical bureaucracy of light aircraft, one study contracted by EASA in relation to ELA-1 legislation is very interesting. Here they looked at accident rates of European microlights (MTOW 450 kg) and US LSA, and compared with other similar activities, light GA (MTOW 1200 kg), ballooning and gliding. There are some holes in the material since microlights are not normally under CAA legislation and not EASA and there are great differences from country to country, but the conclusion is crystal clear, and virtually identical to what was found in the USA (experimental vs certified).
The safety outcome appears primarily dependent upon pilot training and subsequent
continuation training & education within a supportive environment. With such measures in
place the safety outcome is comparable to other sectors of recreational aviation such as
gliding.
The general conclusion from microlighting therefore was that the fatal accident experience
where initial airworthiness was the primary cause, was no worse than that experienced in
the ‘fully regulated’ light aeroplane sector. This is significant. Also significant is the fact that
accidents involving fatalities to ‘uninvolved’ third parties are almost unheard of, whether for
microlights, CS 23 aeroplanes, gliders or balloons. The risks based on empirical evidence
are limited almost exclusively to the occupants of the aircraft, or people on the ground near
the aircraft when moving.
etc etc
All the reports and data can be found here
