There seems to be an issue with the dropdownlist and the option Label
It is also happening in the demo page:
http://demos.telerik.com/kendo-ui/dropdownlist/cascadingdropdownlist
The optionLabel is displaying in the dropdown where it should not?
See the red arrow on the screenshot (from Chrome on windows)
It is also happening on iPad and definitely funny (attached a screenshot from my project for additional info)