Overall I agree, but Mesos is still big for the frameworks around big data and stateful services. Kubernetes doesn't have the same level of good operators/contr

Overall I agree, but Mesos is still big for the frameworks around big data and stateful services. Kubernetes doesn't have the same level of good operators/controllers for heavily stateful services yet, and the ones that do exist aren't very mature. With time I believe this will get better, but lack of mature client libraries in Java is probably a good reason why this is currently the case. Most of these stacks are all Java based. The people who write software that uses Mesos, or work on Mesos, which is all Java based don't have Kubernetes libraries with the same maturity as the Go based libraries. So it's either wait/fix the Java libraries, or write (and maintain?) an operator in a language that isn't what you regularly use.