FWIW, I've genuinely spent time trying to use it, and I've never managed to run any non-trivial query on it without having it time out. SPARQL is very expressiv

FWIW, I've genuinely spent time trying to use it, and I've never managed to run any non-trivial query on it without having it time out. SPARQL is very expressive, but its implementations seem impossible to optimize and as a result impossible to use because they have to be locked down so tight.