One reason why you might want to bring two clauses closer together is because they make a good contrast.
My father loved it; it scared the hell out of me.
The semicolon brings these two statements together, as if they are two sides of the same coin.
My mother loved cheese; I hated it.
They wanted to the trip to go on forever; I couldn't wait for it to end.
She thought the movie was the best thing she had seen; I would rather have spent the night in a basket of rats.
