This issue reminds me of "music piracy". I'm just old enough to have experienced the tail end of vinyl records and the early adoption of music CDs.
In the early 1990s, there was no way to "rip" a CD into mp3s, or even burn a CD image at home.
Cassette tapes were king, Every teenager I knew had "mix tapes" of their favorite songs. Making these were a labor of love. You had to understand the available length of tape on each side, and plan your playlist accordingly. Further you had to record in real time. A 90 minute (45min per side) tape took that long plus time to pause, flip the record, advance the track, etc. etc.
The reason I brought up that was not for nostalgia, but that behavior was ubiquitous with American youth 25-30 years ago. We never heard of any legal consequences of doing this. Fast forward to the mid-late 1990s, where MP3s came out. Suddenly any moron could click their mouse and get any song imaginable in perfect quality.
That's when the music industry and regulators lost their stuff. I admit, it's still difficult for me to morally reconcile how borrowing my friend's Van Halen album and dubbing it onto cassette was ok in 1989, but downloading the same album in mp3 format was a soft form of organized crime in 1999.
Back to DIY guns. For the cost of a decent sandwich, a slam-fire shotgun can be manufactured from parts in the plumbing aisle at Home Depot. As it's been said, many hobby machinists could make "real" gun parts that work better than 3D printed ones.
This is all emotional reaction. Nothing is materially different.