Here are half a dozen reasons why I support the Jussieu Call for Open Science and Bibliodiversity, roughly in ascending order of importance.
(1) I support its call to move beyond PDFs. This is necessary to bypass publisher locks and facilitate reuse, text mining, access by the visually impaired, and access in bandwidth-poor parts of the world.
(2) I applaud its recognition of no-fee or no-APC open-access journals, their existence, their value, and the fact that a significant number of authors will always depend on them.
(3) I join its call for redirecting funds now spent on subscription journals to support OA alternatives.
(4) I endorse its call to reform methods of research evaluation. If we want to assess quality, we must stop assuming that impact and prestige are good proxies for quality. If we want to assess impact, we must stop using metrics that measure it badly and create perverse incentives to put prestige ahead of quality and access.
(5) I support its call for infrastructures that are proof against privatization. No matter how good proprietary and closed-source platforms may initially be, they are subject to acquisition and harmful mutation beyond the control of the non-profit academic world. Even without acquisition, their commitment to OA is contingent on the market, and they carry a permanent risk of trapping rather than liberating knowledge. The research community cannot afford to entrust its research to platforms carrying that risk.
(6) Finally I support what it terms bibliodiversity. While we must steer clear of closed-source infrastructure, subject to privatization and enclosure, we must also steer clear of platform monocultures, subject to rigidity, stagnation, and breakage. Again, no matter how good a monoculture platform may initially be, in the long run it cannot be better than an ecosystem of free and open-source, interoperable components, compliant with open standards, offering robustness, modularity, flexibility, freedom to create better modules without rewriting the whole ecosystem, freedom to pick modules that best meet local needs, and freedom to scale up to meet global needs without first overcoming unresponsive decision-makers or centralized constraints.