Sorry, this is wrong. A segfault means you got lucky and your bad memory access hit an unmapped or otherwise invalid page. Other times the program will keep running with incorrect results. Many such issues represent exploitable bugs.
In any case it's a bad issue and should not be a normal failure mode for a syntax error.
"Other times the program will keep running with incorrect results. Many such issues represent exploitable bugs."
None of which matter if it's a prototype, running on a developers machine.
If you want memory safety you run the program through valgrind anyway with a large input dataset. And write unit tests. And integration tests. And so on.
The baggage of production quality software development environment is so high it easily stifles the joy of quick and dirty prototypes.
The main use of prototype is to facilitate understanding. This is the most critical constraint, whose needs drive over anything else.
Besides, who on earth is going to exploit a few hundreds of lines of code a developer runs on his or her own machine?
I don't know if you noticed this but C hackers are a minority on here. Thus it's not unreasonable to think people get an impression of how C is done from submissions here. We owe it to the craft to serve as good examples. It's not as burdensome as you suggest.
I see your point, but respectfully disagree that an incomplete implementation should stop a submitter from sharing his or her discoveries. This is an aesthetic position - I think interesting ideas are more important than clean implementations (It is left as an exercise to the reader... is an ok position, IMO).
In any case it's a bad issue and should not be a normal failure mode for a syntax error.