We all love to hate the big publishers that are bankrupting our libraries (is it true that UK universities only spent 2.7% of their budgets on libraries? something's wrong there). But not all publishers are exploitative - many University publishers run as not-for-profit corporations. And publishers don't retain all the profits of journals. Far from it.
I've been associated with two journals which have completely different models: the learned society model and the collective ownership model. In both these models, the publishers have a contract to publish the journal, which usually guarantees them a % of the profits, the rest is passed on to the learned society or collective group of academics.
Learned societies, which rely on these not-inconsiderable sums to run conferences and support their administrative overheads, would also suffer under the proposed Gold Open Access business model. A journal which publishes 20-40 articles in a year would have a maximum income of £40 000 - £80 000, if authors paid £2000 to publish with them (some are arguing this amount would be much lower). That may be plenty for a publisher that owns and runs hundreds of journals. But it will be a blow to the learned society, which relies on their income for many good purposes - usually using it to subsidize conferences, and sometimes to provide honoraria for editors and book review editors.
In particular, collectively owned African studies journals such as those started in the 1970s have used the 'windfall' profits of publishing to sponsor travel of African academics to attend conferences and present papers, or send their members to attend conferences and workshops.
These journals also tend to have extremely reasonable subscriptions, which are set at cost for members, or even subsidized. If they lose subscription income from libraries then small grants that have sustained annual conferences and one-off workshops may disappear, along with the ability of learned societies to administer their membership and represent their interests. Academia will be poorer, because these journals will pay the price for the rapacious behaviour of Elsevier and a few other 'big' publishers.
The Finch report, rather condescendingly, tells learned societies to 'diversity their income' as if they've not been doing this for years? Yet more additional burdens for the academic community to shoulder, as we struggle to in search of an elusive work-life balance.