America has indeed become overly litigeous.
However, lawyers working on a contingency fee (based on them winning the case) was/is/can be very helpful to those who have been severly injured, or wronged, who would never have access to the funds required to hire an attorney.
Like most things in life, there are those who find ways to abuse it. But... I'm not certain it would be any better if this option weren't available to those without money.
As far as lawsuits against Carnival, while no doubt there will be some frivilous claims, I do think there are questions that need to be answered by Carnival.
I'm not so sure they should just be let off the hook completely, without total investigation, just because they've suffered the financial consequences of the event already.