While it is the scientists who are writing the papers and editing them, the journals provide a valuable service as intermediaries between the scientists. Whether this service is best provided "for free" or for profit is another question. In some fields, the leading journals are already published by not-for-profit organizations such as the ACM, but I am not sure that they are doing a better job than Springer or Elsevier.
In a language that's understandable to the HN crowd, journals:scientists are as VCs:(founders + investors).
In a language that's understandable to the HN crowd, journals:scientists are as VCs:(founders + investors).