What does "rationalized" mean? Highly respected open access publishers like PLoS charge similar fees https://www.plos.org/publication-fees - maybe that's just what it costs to run a journal? If not, PLoS must be some ridiculously profitable scam.
But yes, the (well known) profit margins of some of these publishers are quite simply obscene.
[1]: https://scholarlykitchen.sspnet.org/2015/09/29/plosone-hikes...
Right, so the incoming money is spent on the company itself - so should represent the long term running costs, surely.
> And PLOS, like for-profit publishers, has in the past had very large profit margins (and has been criticised for this, e.g. [1]).
I'm not sure I'd say those are extreme, $5M on $50M in revenue. Even if you removed that you would still have APCs of ~$1450-2700 which I don't think would change the original point.
“Non-profit” does not mean an organization does not earn profits. It means that it is not a vehicle for returning profits to particular stakeholders (owners, shareholders, LLC members, etc.)