I agree that homeowners should be able to do their own work but that doesn't mean that they should have easy access to materials. Years ago DIY electrical wasn't as much of a problem as it is today. We can thank the big boxes and the DIY shows.
30 years ago the only place you could get a panel is at a supply house and if you were a DIY homeowner they would throw you out.
-Hal
I think you are just looking back with that 'it was better back then attitude'
This country was built by DIYs, the carpentry, the wiring, the plumbing.
You say homeowners have a right to work on their home but at the same time you want restricted access to parts.
That will result in people using whatever they can get their hands on or a black market of parts.
The DIY shows and stores did not create the do it yourselfer, they just saw that the DIYs where out there and aimed to serve them.
My own home is a 1925, I bought it from two brothers in their 60s, they explained how their Dad built the entire home himself. His real trade? He was a local butcher. I doubt he ever saw a DIY show or store.