The answer to almost any question beginning with "why don't they" (or why didn't they), is almost always "money". Producing, aggregating, storing, or otherwise

The answer to almost any question beginning with "why don't they" (or why didn't they), is almost always "money". Producing, aggregating, storing, or otherwise adding value to information costs money. Operating the internet costs money. Providing access to data costs money. People are lazy. Businesses on the internet have learned that they can extract more money from this vast pool of lazy people by presenting information rather than just providing information. By this, I mean that the value-add and/or lock-in of many internet businesses is tied to how the information is presented; adopting a standard format would be effort that would not be financially rewarded. (by "lazy", I mean "looking for local minima in effort to accomplish whatever task that they're trying to do") Finally, the web envisioned itself as a hypermedia system that incorporated presentation (and subsequently active content) instead of just semantic content. Since presentation is a property of the web, it was quickly adopted for the reasons described above and evolved into the modern web (which replaced the blink tag with shit tons of javascript, don't get me started). Therefore the "semantic web" could never exist because "semantics" is fundamentally incompatible with "web". Once you invent the web, you can't have the semantic web anymore because money. We shoulda stuck with gopher.