The reliability numbers are a bit alarming.
However, it's surely an anomaly, since the F135 was mature six years ago...
The F135 is established and mature, with production engines set for delivery later this year after more than 12,000 hours of testing. It is also based on the proven and highly successful F119 engine powering the F-22 aircraft, meaning testing and operational performance on that fielded engine has pushed the F135 engine even further along its path to maturity.
http://tinyurl.com/135mature
Or at least, that's what the people in the know, doing the real work, said. And of course they must have been right.