All things are relative. Improvised firearms("zip guns") have long been made by prisoners, partisans, and others who have otherwise been prohibited access to conventionally manufactured weapons about as long as there have been firearms. They've been made from soft metals, wood, plastic etc. I suppose the users have conducted a rudimentary cost-benefit analysis and found that the risk of their firearms failure was an acceptable alternative to going entirely unarmed.
And certainly, while I would not want to be holding one when it blew, both the prior design from a week or two ago and this one fire the .380 which is a (relatively) low pressure cartridge which actually has a lower recommended chamber pressure than a .22 LR, which would minimize the collateral damage in the event of a catastrophic material failure.