Unfortunately, the more parts put into a device, that can and is enclosed by a pretty cowl, the more overheating it causes. Which shows up in some nasty problems, because it cools off on the landing approach.

Magnetos on outboards run for over 50 years. Snowmobiles 30 years. How many of todays Hi-Tech engines will be running 15 years from now ?

Hi-Tech -- CAN be another way of saying. Make it cheaper. The customer has few choices.