True, it is not too much of a sales pitch, but still something that really can't be seen as impartial, for natural reasons (it comes from the company behind Mesos) and it looses a bit of clarity (Java doesn't equal legacy, you can run Stateful workloads on Kubernetes) towards the end.
From my point of view, the benefits of the two level scheduling are actually quite limited with respect to how the whole story is usually told. Some Mesos framework always use all the resources from the clusters and it might get tricky to really have multiple frameworks to run at the same time on Mesos. Also, sometimes those frameworks don't really offer so many additional features to justify changing the way you are already using Spark, Cassandra and so on.
From my point of view, the benefits of the two level scheduling are actually quite limited with respect to how the whole story is usually told. Some Mesos framework always use all the resources from the clusters and it might get tricky to really have multiple frameworks to run at the same time on Mesos. Also, sometimes those frameworks don't really offer so many additional features to justify changing the way you are already using Spark, Cassandra and so on.