I don't think kubernetes is to blame for that. One of the facets of a really complex system is that there're way more moving parts that a generic system can handle or anticipate all possible failures. Sure, with time, kubernetes might get a mature native monitoring setup or expose a higher-level support for monitoring than what's currently available in terms of cAdvisor/heapster and health endpoints. So we built the simplest thing to achieve what we needed at certain point in hopes that the simpler it is, the less "monitoring the monitor itself will require".

Yes, I see prometheus as a step towards a more sophisticated monitoring setup if you consider (and enable) this as a prometheus service. Satellite can push metrics to one of the prometheus servers for all the benefits prometheus provides. So neither is really a replacement - rather a complement. Satellite was born out of immediate need to monitor the cluster as it is being created and definitely appears naive in most other respects - it implements just the bits to do that. So, pairing it with an established solution like prometheus (or InfluxDB, for that matter) is an undeniable benefit.