It was the answer to a problem that nobody had, straight out of the dotcom bubble days where those answers could be sold as a business cases or for university grants.
Basically any form of structured data, be it in XML or JSON, served through some channel of data, is everything people need. There is no benefit in further standardization. Simple, informal standards work better than monstrous specifications that nobody ever bothers to deal with properly. The most important part is reducing friction, that's why JSON is the most successful format despite its shortcomings.
One being that while a set of SPARQL Federated Queries would elegantly replace my assorted, custom collection of python scripts, scrapy and PhantomJS (slowly porting over to puppeteer) programs talking to Postgres, there is no usable graph store you and I can use as of 2018.
Another being about monetizing the Semantic Web when playing the role of the data/ontology provider.
The majority of your clients will want your data in relational formats than turtle/RDF files/format anyways.
Basically any form of structured data, be it in XML or JSON, served through some channel of data, is everything people need. There is no benefit in further standardization. Simple, informal standards work better than monstrous specifications that nobody ever bothers to deal with properly. The most important part is reducing friction, that's why JSON is the most successful format despite its shortcomings.