From the O'Reilly Network weblogs: XML complexity as war of attrition [September 24, 2002]

As Simon says, if you have lots of developers a good way to beat off the small upstarts is to make them spread their limited resources across a range of targets. If you can convince potential customers that these things are must have features then the small developers are always playing catchup; implementing features just so that a customer can check a box on a RFQ for something they will never use.

As well as complication and extension of existing standards another technique is software churn. Every three years introduce another platform or technology, convince people to switch, which should get rid of some competitors along the way, and then do it all over again.

Perhaps the time is getting ripe for another disruptive markup technology :) The functionality in XML is starting to outstrip what people need. An upstart now has a chance if it offers to some class of users some features where it beats XML. Possibly easy to write by hand or targeted to some particular XML use, or having a simple macro facility (though you might as well use SXML in that case and get full scheme support). I don't know what's coming next but when complexity reaches the level it has with XML people are going to want a simpler solution to deal with 80% or less of their problems leaving full XML for the rest.