There was a very interesting article in the Guardian Review section on 16 May about the fate of serious non-ficiton in today's market.
Having worked in academic libraries for almost 20 years, I know there is a place for serious texts with a small readership. But it has to be said that too many books were published in the past without making them the slightest bit interesting. Many of the academics I worked with would have thought they were letting the side down by being easy to understand.
Certainly any academic writing books that a wider audience could enjoy were regarded as selling out. Even today, there can be a high level of peer criticism about books that appear short on seriousness and high on "easy to read".
I think that's nonsense. Of course we need people who aren't swayed by any need to be popular, but at the same time opening up subjects can have a major impact on people who suddenly have a door opened into a topic that had been difficult for them before.