A lot of class action and other "private" civil litigation should be viewed as more "public" than "private."
On a spectrum, I conceive of "private" litigation at one end of the spectrum being one human being having injured another human being and the latter suing the former for damages, and only those human beings are affected by the outcome of the litigation.
Where there are corporations and other organizations comprised of conglomerations of human beings in various roles and functions, there are many human beings who are affected by the outcome of litigation. They may be shareholders, officers, or employees of a corporation, and they are differentially affected by the outcome of litigation. Some of these human beings (officers and employees) have culpability for making decisions and carrying out corporate activities that cause the injury, whereas others (shareholders, other employees) are largely innocent bystanders concerning the corporate wrongdoing
Further, costs of litigation against a corporation can get spread in a more public and notable way to customers in the form of higher prices, than happens as consequence of litigation way on the "private" end of the spectrum.
Also, there is more visibility and particularity in outcomes of bigger scale litigation that cause other persons and corporations who are not party to the litigation to modify their behavior. This is especially true when the law imposes big liabilities without there being intentional wrongdoing or negligence, or with very slight negligence.
In evaluating this "public" litigation, there are meaningful questions about whether the work of plaintiffs lawyers well serves or ill serves the societal interests that are involved, and whether state attorneys general and other publicly accountable officials such as government regulators and district attorneys would better serve the societal interests.
Due mainly to the compensation arrangements for plaintiffs' lawyers, I contend that it would be better if state attorneys generals and other public officials were responsible for bringing and prosecuting of this "public" litigation. For discussion and arguments in support of this contention, please see these two blog entries, among other entries: Does the Civil Liability System Undermine Business Ethics? and http://robertshattuck.blogspot.com/2007/11/alabama-supreme-court-elections-1994.html:
As a result, I am an advocate of an expansion of the domain of the state attorneys general in the bringing and prosecuting of this "public" civil litigation, a hiring of more lawyers by those offices, and a reduction of the role of plaintiffs' lawyers.