Granted, Netflix had to build their own pipeline based on open source technologies. They used the right tool for the job. They used a NoSQL solution for reliably gathering/recording their data at scale. They used an RDBMS where it made sense.
Netflix is a big company. They can build their own data processing infrastructure from the various pieces. However, what about all those smaller companies that want to collect and process data that is critical to their growth, competitiveness, survival? Wouldnt they benefit from cloud solutions that are scalable, reliable, and NOT managed by them!