I think the people really pushing for the Semantic Web kind of gave up. You hardly ever hear that term anymore.
I guess the value proposition of "You can add a whole bunch of complexity to your webpage that won't affect what people see so robots can scrape your page easier" didn't really resonate with developers. Also, the proposals I saw were much too granular and focused on people writing scientific papers on the web. It wasn't a good mesh for the "garbage" web, which is like 99% of everything.
I guess the value proposition of "You can add a whole bunch of complexity to your webpage that won't affect what people see so robots can scrape your page easier" didn't really resonate with developers. Also, the proposals I saw were much too granular and focused on people writing scientific papers on the web. It wasn't a good mesh for the "garbage" web, which is like 99% of everything.