I use mine all of the time. It does a few things that a bandsaw cannot, and works a lot faster than a coping saw or fretsaw. One of it's biggest advantages is cutting out a hole in the middle of something. It's also great for tight turns, especially with something like letters or numbers. It's also used for marquetry and inlay sometimes. And I've used it to make saw handles and other things like that on several occasions.
But, if all you do is make large scale furniture, then it probably won't see much use. I use mine mostly for small things and detail work. It rarely gets used when making large pieces of furniture. It's definitely not a "must have" tool for most people, but it can be for some. And, one of the great things about a scroll saw is they're small and you can get a good one for relatively cheap. Mine's a Wen brand (I think I paid about $100 for it), and it does everything I've asked of it very well. I keep it in a cabinet and only pull it out when needed. It's especially nice because it holds both pinned and pinless blades.