To me, it's irrelevant, that some people don't enjoy the shows. The fact is that NCL was known for offering large Broadway style shows and its something that distinguished it from some of its competitors. I really don't gamble but that doesn't mean that I think there shouldn't be a casino. People enjoy it and expect it on a cruise just like they expect to be entertained.
Royal is the other line that is known for entertainment. After not having a Broadway style production on Odyssey and Wonder, they brought it back for Icon.