In most cases the journals are edited by the same people who write for them, for free (sometimes there'll be a pittance salary, but it's not enough to quit your day job by any means).
The "incomprehensible gibberish" is, in general, fully comprehensible by their intended audience, which is other academics working in the same field.
Here's how the model works:
1) Academic writes the article, supported by taxpayer funding, or a grant from a foundation, or whatever. 2) Academic submits the article to the journal, where it is peer-reviewed and edited by other academics. 3) None of these academics get paid a cent for their work (other than the aforementioned public funding). In specific, the journal publisher doesn't pay them anything. Some of them even CHARGE the author. 4) The journal publisher then sells the result for hundreds or even thousands of dollars per year.
Nice gig for the publishers. Less so for the academics and the taxpayers.
This model made a certain degree of sense back when journals had to be printed (short print runs are expensive, especially stuff with lots of diagrams, weird equations, foreign languages, etc. as journal articles tend to be), then physically distributed by paper mail to institutions all over the world.
That's no longer the case.
