Obviously no one would search a completely random hex, but it may represent an ID somewhere, and they want to find out more information about it. e.g. a SHA or MD5 hash.
Agreed, you can look up d41d8cd98f00b204e9800998ecf8427e for example. The question is how critical is it that Google returns a non-useful result vs a page that says there are no results. I think most people don't care, it's not useful either way.
