Why does every file have to be a PDF?!

Why does everyone think that every single file on a computer has to be a PDF?! At least once a day I either take a call, respond to an email, or read a question on a forum about someone wanting to take a file, ANY file, and turn it into a PDF. An architectural design to submit to a guy's boss, and the boss wants it in PDF. A picture file, a simple JPEG, needs to be a PDF for you to email it and your client to open it? Kinkos accepts ONLY PDF files and no other format whatsoever? Why do people believe that a PDF is the only file format that everyone can view?

You do not need to take a JPEG and convert to to a PDF in order for you to print it, email it, or show it to someone on your computer! I spoke to someone yesterday who wanted to do this (JPEG to PDF) because he didn't want the person he is sending the file to to "alter" his picture. And I mean picture. He is sending someone a picture! How does making it a PDF prevent someone from altering the file? Anyone who would have the ability to "alter" a JPEG has the knowledge to "alter" a PDF as well.

I am utterly confused where this desire to make every file into a PDF stems from.... any thoughts?

This one had me laughing....

A guy trying to use Vista's voice recognition feature to do a little typing.