ODF, Why! Is that XML! Why?

Why is ODF popular? Perhaps I should be asking why XML is popular as a file format, compared to OTF commercial formats? I like XML since I can process it with any one of many apps. I know the format, I can read it using many tools. I hope it will remain largely unchanged over the next 5 years.

I've been on the losing side of an ODF debate recently. The (nominally trivial) subject was whitespace. The opposite viewpoint (my words) stated that whitespace was unimportant. What they see as important is that the presented visual page is consistant. My view is that after n years of suffering from revisions of commercial products organizations are keen to have a file format on which they can rely. Not just for this week, but for some time to come. I.e. a number of years. There is nothing more infuriating that trying to read (Mr|Mrs|Ms) X document from n years ago, by hunting for a convertor. XML provides a format which can be hacked quite readily by a number of applications. IMHO that is (one of ) the reasons that ODF is found attractive.

It would appear that implementors find the view of the document on the screen the definitive article. That is the perspective that must be retained across implementations. How these people see that as important when Microsoft Word version X is seen as historical, WordPerfect Y is seen as historical etc, I really don't know. Perhaps if you've just put out revision xyz of an Office suite then it just is important? It can't be bettered? I don't know, I've never done it.

The proposition seems to be (for ODF 1.1) that applications (XML applications ala xml 1.1 definitions) can screw with an authors whitespace to their hearts content. If it's at the start of an element, dispose of it. If it's mid element replace it with markup. To me it seems weird. To implementors (IBM Sun and so on) it apparently seems the thing to do... the only rationale I've heard is that it makes XML presenation easier.

Why that one codepoint out of Unicode is picked on I really don't know. The warning perhaps is look out   and the variants of space up near 2000, perhaps you're next in line for the ODF mafia?