Basically, the Curators on Medium staff won't tend to accept a Boost nomination if it 'only' contains factual detail which could easily be found elsewhere online and nothing which gives it a 'unique' flavour.

Nominators are in the middle here, between great writers who send them marvellous pieces of work and the Curators who have set rules they adhere to. Essentially, they are thinking of business - writing which a lot of readers will find something memorable in keeps them coming to Medium. Nominators do also have their frustrations over work they think is well worth further distribution (which is all boosting is), as all we can do is recommend and 'suck it up' if it gets rejected.