I'm coming into this late but I have to tag in so I can keep up with this thread. I never had much trouble with Dumas but I admit that Victor Hugo had me gnashing my teeth at times in Les Miserables when he would, for instance, spend multiple chapters describing exactly what a "guttersnipe" is only to say that the boy the story was about was not a true guttersnipe because his heart was "absolutely gloomy and void." He gave a long and detailed description of the Battle of Waterloo only to introduce a character wandering on the battlefield after the battle was over. I guess when you're paid by the word you do what is necessary to maximise your earnings.
