Engine Failure problems of the 2015 Mazda CX-5

2015 Mazda cx5 2. 0 l, well maintained; recommended oil used at proper intervals, with 130,000 miles, mostly highway driven. With no warning lights and/or sounds, vehicle started loosing power at around 30 mph in the city and engine completely stalled. Aaa was called to start the vehicle to no avail, battery checked out ok. Towed to Mazda dealership in wichita, KS. Dealer service examined vehicle and found a valve stem broken and lying on top of engine, visible through the spark plug well. As the owner, along with the service manager, I saw the broken valve stem in the engine but also notice my engine was extremely clean on the inside with clean oil as well, no evidence of dirt and/or sludge of any kind. Vehicle owner commented to the dealer how clean the engine and the vehicle was kept inside and out. Dealer responded by text to owner, new engine replacement, at the cost of $7000; used engine with 91,000 miles at $5000. Dealer stated after 60,000, vehicle of out of warranty. Owner researched and found evidence the failure is likely due too engine design. Mazda built an aluminum engine with high compression ratio, but built it lighter and with smaller component parts. According to engineers, that's a recipe for various component parts and ultimately overall engine failure. The skyactiv engine operates at 13. 0 compression ratio, by design; if not designed properly and being it's new technology, failures like internal component parts and the engine, are likely. Owner's vehicle at dealer for almost 3 weeks and they are offering no assistance to repair the vehicle. There needs to be an inquiry into the design of the skyactiv engine and address Mazda alleging owner's are abusing vehicles and charging exorbitant prices for mechanical issues caused by their product design. Owner currently has two 2015 Mazda cx5's . Dealer/Mazda offering no assistance.