I too have no doubt that the Rotax 912, most Lycomings and Continentals are more reliable than Jabiru engines but none are as reliable as turbines. It's all relative.
Jabiru engines were developed out of necessity when there were much lower weight limits for our aircraft and no four stroke alternatives with the required power to weight ratio available. The 912 may have been available but too heavy for the early weight limits.
No doubt Rod and his mates are the type of blokes who don't mind a challenge and went for it after KFM let them down. We seem to be overlooking the fact that Jabiru have pretty humble beginnings (compared to Rotax who have a massive company behind them - Bombadier who not only produce engines for aircraft but jetskis, snow mobiles, lots of motorbikes.....). If Rod and co at Jabiru had 600 kg to design to back in the '90's they probably wouldn't have bothered developing an engine. Imagine, the 170 with a 912s, they'd have to work well together. Anyway, the Jabiru engine manufacting industry is established and very successfull and has allowed many people to get into the air in a variety of aircraft. I'm on my second Jabiru powered aircraft, the first being Corby Starlet 28-3381 (no longer owned by me but still going great and much loved by its current owner) and my current UL 450.
For me, there is a certain amount of national pride in Jabiru's achievements. Hearing the incessant and often hasty, uncalled for put downs by some, is in a way offensive. You've got to smile and think 'what the heck' when some of the most vocal critics of Jabiru have proudly displayed in their avatars that the aircraft they fly is powered by an engine with a 300 hour TBO. So far the only real engine failures I have experienced have been in aircraft powered by these.
I understand that Jabiru engines are a work in progress. So too are all other aircraft engines although Jabiry may be a bit more intensive in their requirement for vigilance. I also understand that flying is dangerous and there is no such thing as an infallible engine, aircraft or pilot. There are no guarantees on a safe return from any flight - that's why we should perform a careful risk assessment prior to any flight (or drive to the airstrip....).
Laurie