You're making the error of assuming that all web applications in production have the same user base and constraints as yours. For example, I work on an applicat

You're making the error of assuming that all web applications in production have the same user base and constraints as yours. For example, I work on an application that is a companion app to some larger domain applications that themselves only work on newer versions of Chrome and Firefox. I defacto don't have to support IE, as none of my users can use it. Additionally if you make a developer focused tool like bug reporting, APM, or log aggregation, you can probably ignore IE, if you don't target Windows devs.