I used to work in this field (academic journals), and assuming Elsevier is like every other publisher, then the journal holds the copyright for the article once it’s published, unless the work was done on the government’s dime. Authors are typically given a form called “Transfer of Copyright” that explains this and which they have to sign. This isn’t some evil, Big Brother censoring–they’re just enforcing the agreement the authors entered into, and as others have pointed out, there’s a non-trivial amount of work that goes into producing those journals.
Granted, Elsevier has engaged in plenty of other shady behavior–especially in terms of subscriptions–but this isn’t one of them. The question of whether there’s a different/better way to do this is one worth having, but at least in terms of how the current model works, there’s nothing nefarious going on here.
