Because the word from the few people who actually think that Capcom is a good company is that Capcom will be sellouts if they go back to the original DMC series when clearly they have no clue that Capcom have been sellouts this entire generation.They will be really silly if they went ahead with a DmC2. I don't see the point.
Why pander to a small group of hipsters when there's a larger group of fans who'd buy a faithful DMC sequel in a heart beat?
Capcom wouldn't think twice about turning Street Fighter into an RPG game if it guaranteed to make them more money.