Three thoughts:
1) I found his advice very good at a time when I was struggling with debt more than twenty-five years ago. I am in far, far better financial shape having taken his relatively simple advice that I had not heard anywhere else. Therefore, I'm in far better emotional and mental health, as my wife and look forward to a comfortable retirement.
2) If he promoted a dishonest company that ripped off its clients, he is liable for their losses. It's not like a baseball player advertising a beer brand. Ramsey was trusted as a financial advisor and his advice about time share was taken by his listeners as professional advice, not advertising for which he was paid. I'd be glad if the people damaged by his advice were made whole.
3) They won't be of course. Not in a class action lawsuit. Class action lawsuits are enrichment schemes for trial lawyers. They will get millions in contingency fees and pass on pennies on the dollar for their losses, after deducting for expenses. Judges to whom the mass tort lawyers make maximum campaign donations will rubber stamp the compensation plan if they win the case.