DVDs vs. Office Documents
The difference between a DVD and an office document is that everyone produces zillions of documents and spreadsheets, but only a small number of organizations produce DVDs or USB devices or whatnot.
It is important that every software developer be able to write software that reads and writes office documents in the standard format. Why? Today we all have OpenOffice and MS Office, and this debate is too often framed in terms of a contest between those two applications. But that misses the issue. Everyone produces office documents, and in the future there will be zillions of pieces of software to read them, analyze them, write them, index them, transfer them, etc. For example, the database application I wrote does a simple mail merge, producing an ODF file as a result.
Some of the software that processes office documents is GPL'd, some is under commercial licenses, some under public domain. Excluding an entire class of software from being able to read and process office documents would not be good for society. What would things be like if commercial software were able to do mail merges, but GPL'd software was not able to do mail merges, at least not in a document format that anyone can read with their other programs? That's kind of like what we have today in terms of commercial OS's being able to play DVD's, but not Linux distros.
But it's worse, because processing office documents is an essential feature for computers, while playing DVDs is not. You put a lot of work in making your documents, and you should be able to use any software you wish to process them. After all, they're YOUR documents, not Microsoft's.