Could it be because people are unsure how the class plaintiffs could be subdivided and lengthen the process that could take on?
From the opinion
"For those who purchased their shares after the enactment of the Recovery Act and the FHFA’s appointment as conservator, the analysis should consider, inter alia, (1) Section 4617(b)(2)(J)(ii) (authorizing the FHFA to act “in the best interests of the [Companies] or the Agency”), (2) Provision 5.1 of the Stock Agreements, J.A. 2451, 2465 (permitting the Companies to declare dividends and make other distributions only with Treasury’s consent), and (3) pertinent statements by the FHFA, e.g., J.A. 217 ¶8, referencing Statement of FHFA Director James B. Lockhart at News Conference Announcing Conservatorship of Fannie Mae and Freddie Mac (Sept. 7, 2008) (The “FHFA has placed Fannie Mae and Freddie Mac into conservatorship. That is a statutory process designed to stabilize a troubled institution with the objective of returning the entities to normal business operations. FHFA will act as the conservator to operate the Enterprises until they are stabilized.”)."