way back when, I did so because I loved the feel of them. It was my Goldilocks moment. The few pastels that I had used before were either to hard and scratchy or way to soft and crumbly. I do like to push a bit when I "draw" so I hope you can understand my problem. Experimenting with different chalks, clays, talcs, etc. I could change how each stick would feel. Suddenly a whole new experience was opening. I had color that I could push against and it wouldn't crumble and be reduced to dust but left in its wake a beautiful rich intensity. They were smooth without being slick.
This led to a group of drawings using this wonderful new color line without end.