Everybody agrees they only last so many rounds, and I assume one would really not want to be holding it when it fails.
You're right, but as a former mechanical engineer, I wouldn't have expected a plastic gun barrel to survive a single test-firing.
So if plastic guns are already surviving 9 test-firings, it's not unreasonable to expect them to be safe and practical soon.
I find it amusing that they chose the name “Liberator”, after the Liberator pistol dropped during the resistance in Europe.
The wannabe overlords know the tale as well as we do.
They may have the full auto MP5’s on their myrmidons, but those guys are subject to a well planned ambush with Liberators, and then the resistors have some nice MP5’s as well.