Why the title field is important to SharePoint?

While working on site currently I have had lengthy discussions around which fields to use in Content Types and whether the Title field really is important.  Users tend to historically use the document name to place a description so for example ‘Company Document on Finance Policy V1.1.docx’ is a descriptive document name.  But with SharePoint the Title field is taking away the need to have that long document name.  Use the title for the long worded description and keep the document name simple.

Now by default the title field will be automatically populated with the title from within Office documents although for those who cheat by taking someone else’s document and changing it this can catch you out.   No title field and it will be blank on upload, and the same goes for non-Office documents.

But the title field is important as that is what our search service will use by default for crawling and this is what will be displayed in the search results.  By not using the title field we are making our search more difficult to find the right results.  They say it is 80% ‘putability’ and 20% ‘searchability’ so why is the title field important to SharePoint?  Search is the answer.