Usable = Edible
A restaurant which serves food that is just edible doesn’t have a bright future. Great restaurants make eating into a great experience. The food smells good, looks good, tastes good and is well presented. And it’s edible too!
So is creating edible software enough? No. Successful software should care about it’s users and serve them a great experience. Because those experiences are what create customers who don’t just use your software, but users who love your software.