I've had a similar experience in big companies. While you're learning and you're challenged technically, all is good. Once you master most of it and start asking the deep questions about how exactly you're helping the world (and sometimes more importantly, the means for that), that's when trouble starts.

E.g. "kicking ass" improving infrastructure performance and having fun, then your boss asks you to delay (or never implement) certain improvements because it will be hard to justify the body shop headcount next month.