And during the eons, [ W3C ] have spat out overengineered, underspecified, inconsistent standards that take years to resolve by practical application programmers and browser makers.
Indeed their record has been "rather mixed" as another poster delicately put it.
But I don't know whether they are to blame. There are some industries where standars work, others when they don't. Why can't one put a Ford engine in a Chevrolet car? Or use an HP cartridge in a Canon printer? Why can't one run a Unix binary on a Windows system, or correctly correctly edit a ".doc" file on Unix? Why can't an identi.ca user receive tweets from a tweeter.com user?
In many of those industries, while users would benefit immensely from interoprability and compatibility, the suppliers profit more by "locking in users with incompatible, proprietary products. Thus, instead of a free market, one has a bunch of monopoly markets, one for each supplier.
It depends on the nature of the market, I suppose. Or on pressure by government, either through legislation/regulation of through its purchasing power.