I see estimates differ: I was working from the Sturgeon's Law that '90% of anything is crap' -
- whereas Ridley Scott is prepared to claim that '60% of films made today are “shit”, and of the remaining 40%, “25% … is not bad, and 10% is pretty good, and the top 5% is great”. and that this is pretty much so for the history of the movies over time (a fairly nuanced judgement I suppose) (though we should probably factor in the extent to which film, especially from the nitrate era, was a very frangible medium and there is a survival issue....)
From the Wikipedia article on Sturgeon's Law, some confirming opinions by other thinkerz:
'Nine-tenths of existing books are nonsense, and the clever books are the refutation of that nonsense' (Disraeli, 1870)
'Four-fifths of everybody's work must be bad. But the remnant is worth the trouble for its own sake. (Kipling, 1890)
'In much more than nine cases out of ten the only objectively truthful criticism would be "This book is worthless...'(Wot a grump George Orwell was, eh, 1946)
A 2009 paper in The Lancet estimated that over 85% of health and medical research is wasted.
(The trouble is you cannot tell in advance what is going to be, can you.)
On reflection I rather like Scott's 'not bad - pretty good - great' because one can, in fact, get enjoyment out of those levels.