A suite is a cabin with at least two rooms, right? We thought so, too. And then some cruise lines started offering "suites" with only a curtain separating the living and sleeping areas. Now, we're even seeing some suites that don't have that.
When in doubt, check the diagram of the room layout — all cruise lines offer those on their websites — and see if your "suite" actually is one, if that's something you feel strongly about. We care most when, for example, we're traveling with an insomniac friend, a young child who has to nap, or an older parent who goes to bed early. The rest of the time, it doesn't really matter to us.