Why isn't there an AuthenticationFilterAttribute class in ASP.NET Web API 2?

Question

ASP.NET Web API 2 comes with five filter interfaces:

• IActionFilter
• IAuthenticationFilter
• IAuthorizationFilter
• IExceptionFilter
• IOverrideFilter

All of those interfaces have built-in implementations (e.g. ActionFilterAttribute, AuthorizationFilterAttribute), except for IAuthenticationFilter. Is there a reason for that or have Web API devs simply forgot to provide an implementation for that particular interface?

UPDATE

After reading Yishai Galatzer's answer I ended up implementing the "missing" attribute and uploaded it to Nuget.org: https://www.nuget.org/packages/WebApi.AuthenticationFilter

Answer 1

Because we don't expect the common user to use an AuthenticationFilter. This is a way of not putting it front and center.