File::Temp is not an ill-fitting CPAN module for the purpose of creating temp files. It fits quite well, and is intended to be used almost exactly the way I used it.
Comment on Re^4: File::Temp randomness when forking
For just one example: Something as simple as a system naming constraints can rule out the use of File::Temp. To test your imagination, why not make an effort to think up some more examples of your own?