Microsoft extrapolates

Jakob Nielsen explains why people hate PDF's:
For online reading, however, PDF is the monster from the Black Lagoon. It puts its clammy hands all over people with a cruel grip that doesn't let go. [...]
Here's a quote from a customer who shunned those parts of the site that were in PDF:
"It looks like I'm going to have to go to PDF, which I'm dreading."

Scoble explains how jealous Microsoft is:
Let's see, Adobe makes money off of Acrobat. About a billion a year (Acrobat is funding an entire additional Silicon Valley skyscraper, Adobe's CEO said in a recent magazine article I read). Macromedia makes money off of Flash. Borland makes money off of tools. One of Microsoft's biggest buildings (#42) is full of guys writing tools.

The Palladium/NGSCB information locking is what Scoble is getting at here - he argues that stopping people reading things is the glorious future of profitability for the no-longer-growth-stock MSFT.

Ballmer explains what is really going on here.
A senior partner in an accounting firm needs to send email to his partners with a confidential contract proposal attached. Besides specifying who may read the proposal and that they may not copy, paste or edit the information, he specifies that the email itself cannot be forwarded. The recipients' email and word processing applications transparently enforce these policies. All partners worry less about information leaks that might damage ongoing negotiations.

Ballmer's key mistake here is assuming you can rely on computers when you don't trust people to trust you.

Why are Microsoft so obsessed with this?

I think they still bear the psychological scars from having their internal emails spread all over the papers, and are subconsciously trying to fix this with code...

Personally, I'm all in favour of anyone who thinks this way having their writings made unreadable by others.