Companies such as Green Hills Software and Lynx Software Technology have real-time OS's + middleware that have been used in all kinds of industrial deployments.

https://ghs.com/

http://www.lynx.com/

Maybe the problem is that General Electric is a mega-corporation instead of a company with tons of experience developing embedded software in many markets. It helps to really understand the domain and what users want when developing solutions. Also, only so much can be re-used. Each embedded project is partly a custom job with the amount of customization depending on the use case.