CheckBoxList RadioButtonList and the RepeatXX properties??

[Nobody]

CheckBoxList and RadioButtonList have the same inheritence tree:

-INamingContaine r
-IPostBackDataHa ndler
-IRepeatInfoUser
--ListControl
----WebControl
------Control
--------IComponent
----------IDisposable
--------IDataBindingsAc cessor
--------IDisposable
--------IParserAccessor
--------Object
------IAttributeAcces sor

They both have the following methods:
CreateControlSt yle()
Render()

The both have the following properties:
CellPadding
CellSpacing
RepeatColumns
RepeatDirection
RepeatLayout
TextAlign

BUT!
They don't have a common base object or interface the specifies these
common methods and properties!

Was this designed this way on purpose? If so why?

The reason I'm posting this is that I was trying to write something
like:
if(ctl.GetType( ).IsSubclassOf( typeof(System.W eb.UI.WebContro ls.ListControl) ))
{
((ListControl)c tl).DataSource= dynamicTableDat aSet.Tables["MultiSelectOpt ions"];
((ListControl)c tl).RepeatColum ns=3;
((ListControl)c tl).RepeatDirec tion=RepeatDire ction.Horizonta l;
((ListControl)c tl).DataValueFi eld=dynamicTabl eDataSet.Tables["MultiSelectOpt ions"].Columns[0].Caption;
((ListControl)c tl).DataTextFie ld=dynamicTable DataSet.Tables["MultiSelectOpt ions"].Columns[1].Caption;
((ListControl)c tl).DataBind();
}

In this particular instance I don't really care if the control (ctl)
is a CheckBoxList or a RadioButtonList so why wouldn't they have a
common base object like ListControl that exposes all of these common
methods and properties?????

Thanks for your time.
Scott Wojan