There are many cases where information about the parameters and the call stack is important, not only for the nearest call. For example, you want to prevent the use of the Infobox template directly in articles. But the module can not get this information.
Usually, the module call is wrapped in a template for more convenient use, and hence it is possible to get a frame only for this template. It is not known whether the template itself is called from an article or something else. A typical cascade of template calls before the module is called is 3-4, and these templates can contain parameters that the module needs to know, or which it is desirable to proxy into the module.