Farnborough suffers from the memories of it's past and the ghosts of accidents not so past (not necessarily Farnborough related).
Air shows have declined in general over the years combined with high prices, the economy and the downturn of civil and military aviation.
It's also a victim of our expectations. My first air show without my parents featured two P51's, some WW1 and a black Hunter (plus a few of the stalwarts).
Regs and the council still wondering if they will get `their` Shoreham moment in what is a very built up area.
I suspect the show will eventually wind down.