I suppose the reason why it's hard to find is that it goes against the idea of declarative initialization and the separation of view and model. Your code is not supposed to interact with the widget itself. Instead, all your logic should be wired up in your view model which is bound to the UI.
You can certainly find it without an id, e.g. with something like this:
var treeView = $("ul[data-role=treeview]").first().getKendoTreeView();
or by using the .k-treeview
class, but I wouldn't recommend it. If you really need to access it in code, you should give it an id.