Uh, splitting is very much not natural (at least, I'm taking this to mean artificial splits - if you're saying swarming is a form of splitting, which isn't unreasonable even if it's not the wording I'd use, then disregards this comment). It's part of 20th century beekeeping, yes, but swarming is natural bee behavior, and unnatural practices like splitting, queen clipping, brood cutting, sugar feeding etc. are creating fragile colonies with weak resistance that depend on human intervention (including chemical varroa treatment) to survive.
And this is not just ideology, this is the trend in all apiculture/bee entomology journals over the last say 5 years.