So I was a memcached engineer. The memcached team barely works on memcached anymore, because there are no real returns. Being product focused means that it doesn't make much sense to really increase the perf on something when there's other stuff to be done, even if you could do it in a really glamorous way (user space network drivers spring to mind for this -- that'd be pretty cool)

Instead, they focus on superior libraries and different use cases that make the stack more efficient. (Mcdipper was my project here). In infra, you are measured by two things: 1) dollars saved and 2) features made possible (in a very global way, sometimes this means business deals). You also get points for the site continuing to work