Complex sentence: Some argue that the origin was due to the shape of 1's in the date (November 11--11/11) resembling Pepero sticks, while some others attribute the similarity of shapes as factors that attributed to the popularity but not its origin.
Split into simpler sentences: Some argue that the origin was due to the shape of 1's in the date (November 11--11/11) resembling Pepero sticks. While some attribute the similarity of shapes as factors that attributed to the popularity but not its origin.