From the short article provided, it doesn't sound like the individual claimants are financially motivated, as they will individually likely only see a very small return.
I think class actions can play a useful role in society, being consumer protection. Ideally, governments should play that role, but they do not always have the financial resources, or the interest.
Look at the overdraw and other fees charged by banks. For years these were well in excess of what it actually cost the banks, and often affected people who could least afford it. The government just let the banks run riot for years, so why shouln't somebody bring them to account through a class action? The other argument is that the only people who will make money are the lawyers and the litigation funder. That might be the case, but at least it's helping to curb the behaviour of predatory banks and other large corporations.