the FADEC controlled aerodiesels that use jetA have actually been through their reliabilty problems too, but let us introduce something much more important the bottom line and this new technology is expensive and would raise the cost of flight training in order that they meet aviation reliability [see far 23] if you have the money then there are many options, in fact just get a jet
basically they stopped working on piston recips BECAUSE of the jet engine!!!
also ,simple aircraft such as C-170 etc. are a great deal of the fun when you try to make them into 777 and a330s they just become a mess the systems are simple, the theory is simple and the maintainance is simple, and engine failure is very very rare, for any engine type---it must be so!
BTW my 88 volkswagen has been far more reliable than my 2004 nissan, never compare aviation with automobiles, those things are for the ground---who cares