Suing (or threatening to sue) everyone and anything that speaks poorly about the company is an interesting PR response, isn't it? I'm used to companies just ignoring the issue and hoping it goes away.
It's an extremely common response. I think you're used to remembering stories as "companies just ignore the issue and hope it goes away", summarizing away all the day-by-day coverage of letters they sent telling people to stop being mean, and that's probably how most people will remember this story in a few years too.