Lack of data is a huge problem. In theory the Jab should be more reliable simply because it has less components which could fail. It has no radiator and associated plumbing, no gearbox, no injectors , no injector pump and has a very simple ignition system. There's not much left to fail.
Is it possible it's perceived high failure rate is simply because there are a lot of them around. A lot of Holdens crash but there a lot of Holdens.
Internal combustion engines have been around for well over 100 years. It shouldn't be too difficult too pinpoint Jabs problem area if indeed there is one.
Human nature presents another problem. A mistake be it in installation, maintenance, engine operation or in flying skills is always the engines fault if nobody else saw it happen.
Could human error be why so many incidents go unreported?