Because unfortunately the guys from Richfaces says that
These components works as designed. It is a input component, and not a select component (as it should if you ask me).
You will find tones of rejected Jira issues about this subject. One example is https://jira.jboss.org/jira/browse/RF-3559
My opinion: the component is completely useless as it is.
Something like this should be a priority for Richfaces, Oracle ADF and Trinidad components has the concept of
List of valuesor LOV which is relay helpful in enterprise applications (think that you can not have a drop down with 10000 items to select from... and you want to let the user filter the results).
You can see the demo on Oracle site here http://www.oracle.com/technology/products/jdev/viewlets/11/index.html on ADF Business Components - List Of Values
Here you can find another richfaces jira link with a feature request for this component: https://jira.jboss.org/jira/browse/RF-3565
Status is of course, REJECTED.
I myself thinking to move away from richfaces because the lack of components like this.
Oh GOD! Thank you for that information!
But... which component must i use instead of it. Exists something similar to it?