Things were worse after 9/11 for most cruise lines and certainly stock prices for all. Well, not for NCL who finally got an IPO together not long ago and I think was seriously close to bankruptcy before they got a ton of cash from Apollo or whoever it was a few years back.
If by Freestyle you mean the anytime dining, NCL certainly did not invent it. Bankrupt Renaissance built ships for it long before and perhaps were too far ahead of the curve. Sort of like Carnival Paradise when it was smoke free.
Carnival has been innovative in the past and may be onto something again.
But really, public memory is short lived at best and people are fickle. If Carnival were to spend money on a image issue, I think it would not only be money thrown away, but money that might cause additional undue attention on the cruise line.