the pasteurization process and filtering and preservatives change the taste a good deal.
You can get apple cider in all sorts of flavors, in the PNW gala, Fuji, honeycrisp are all popular ciders at stores.
Also most importantly, I think, most juices and ciders are a blend unless it explicitly says otherwise. Cider is given a bit more leeway in taste but people kind of expect a familiar taste with apple juice.