By swearing and lying, Killing and stealing and committing adultery, They break all restraint, With bloodshed upon bloodshed.(Hosea 4:2) NKJV
Intelligent people are likely to be educated, and mainstream education is to be indoctrinated with the mainstream science narrative of godless existence (SciPop). Rejecting God is a very common outcome.
Is their position of intellectual superiority the reason why they have rejected God and, thus, don’t care about the impact of swearing on their soul? If they have rejected God then his laws are definitely out the window. In which case, why does swearing make any difference?
Hosea 4:2 describes a group of behaviors which are characteristic of the lost. It’s a syndrome. When you see or hear one behavior, it’s an indicator that the others aren’t far behind. Swearing and lying are on the same list.