> getting remedies from a commercial entity is often difficult and expensive--even for a company and certainly for an individual
Depends on the country. The countries I've lived in (Spain & Sweden) both have "Small claims court" which you (as a individual) can go through for relatively speedy (and free) resolutions to minor things, and avoids the traditional (slow) court procedures. This might be EU wide, not sure.
> you seem to be making a case that no one should ever use unsupported open source for anything important
No, I'm trying to make the case that people and businesses need to be more aware of what the license of the software they're using, is under.
If the software license says "THE SOFTWARE IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND" but you need some sort of warranty, then either find an entity willing to provide that for this specific piece of software, chose another project, or fork it and provide your own warranty yourself.