I stumbled upon the following comment in the .NET source code for the ItemsControl class.

In effect, the developer is saying–“I could do this a more elegant fashion.  I just want everyone to know that this is ugly because I was told to do it this way”.

        protected virtual void PrepareContainerForItemOverride(DependencyObject element, object item)
        {
            // Each type of "ItemContainer" element may require its own initialization.
            // We use explicit polymorphism via internal methods for this.
            //
            // Another way would be to define an interface IGeneratedItemContainer with
            // corresponding virtual "core" methods.  Base classes (ContentControl,
            // ItemsControl, ContentPresenter) would implement the interface
            // and forward the work to subclasses via the "core" methods.
            //
            // While this is better from an OO point of view, and extends to
            // 3rd-party elements used as containers, it exposes more public API.
            // Management considers this undesirable, hence the following rather
            // inelegant code.

Who can blame him? I’ve written comments like this myself. Source code as confessional.