Lapsing back in to the Romantic Style for "The Lost World", which was the emotionally reactive prose most popular at that time, made Doyle a lot of money. I have a huge collection of 19th century novels of all types. The Romance type writing so popular then is a bit hard to relate to, but if done well, say by Poe, it is readable yet. I think another reason Doyle used these blatant stereotype characters in Lost was for parody, at least in his mind as he wrote that novel, knowing full well his target audience would not "get it". The book almost comes off like a Vaudville play, with lots of extra dialogue and descriptors, of course. That audience just wanted a "cracking good adventure tale", not something that challenged their intellect, as some of the Holmes stories do. Although literate people back then had a much better grasp of English and basic common sense than today's mass market 50 Shades/Twilight consuming public, they were still mostly scientifically illiterate, even by 19th century standards. With that in mind, as popular as the Holmes stories were, they did not originate as stand-alone publications. They were printed within popular magazines, which sold well regardless and created good publicity for the later published books. However, critics who preferred Romance style novels panned the Holmes stories, and a very large segment of the reading public showed no interest in his Holmes books. "Lost World" and some other books by Doyle were a way to earn some money from that large segment of readership, as they were just the right combination of free flowing fancy and romance.
In any case, there are fine novels of modern prose that would likely be almost incomprehensible even to 19th century intellectuals. These books are not so much a resurrection of Romance style, but the alternate realities and psychological thrillers by authors like Rushdie, Camus, Sartre, Ellison, etc. would be a real challenge for 19th century people to get a grasp on.