Why no Object repository in TestComplete

Actually, yes you can add items to NameMapping by a click of a button... there is an item in the tool bar that allows you to select an object on screen and add it to your NameMapping. From the object browser, you can also right click on any object and add to NameMapping. When recording, Test Complete can automatically add items.

With NameMapping, if the GUI changes, you adjust your mapping without having to change your code. For that matter, there is the Aliases layer which separates the mapping from what you actually use in your code so, if your hierarchy of components, properties, etc changes, you can adjust how an object is mapped while keeping the same alias structure.

While you may not be able to drag and drop into your code (a cool idea, btw, worth suggesting in the feature requests part of this community) both in keyword tests and script code, TestComplete has what amount to an intellisense to the Aliases that makes writing the code easy.

While NameMapping is not the same as UFT's object repository, it has a lot of power. And I can attest in my current project that, when used well, it can actually speed up test development. We recently upgraded the code for one project to another and all i had to do for the GUI changes was adjust a couple of mapped properties and all my tests ran with no code changes at all.