Is it ethical for companies to commoditize open source projects (without giving back!) ?

Is it the case that Sagemaker Notebooks (https://docs.aws.amazon.com/sagemaker/latest/dg/gs-setup-working-env.html) are just commoditzed Jupyter?

As far as I know, Jupyter went through a very rough process evolving from ipython notebooks essentially /w giant amount of effort from Fernando Perez and community. From what I can see (Amazon) now decided to commercialize essentially the end effort of a decade of work without ever really contributing back (e.g. http://jupyter.org/about) to the community.

While this may be legal (re: licenses), is this ethical?

vs the various other consulting companies built around an open source offering (e.g. Red Hat) or that also contribute back to core dev while selling an offering (e.g. Cloudera)