You know, it doesn't matter. I used to make my own all the time, usually smooth. I could stop the blender at any point. The longer you let it go, the smoother it gets. It's still nothing but roasted peanuts and a little salt.
Roasted peanuts and a little salt. That's all it needs to be.... except I'll take crunchy over smooth any day. And since I don't eat peanut butter cookies or anything other than with bread or a cracker, no reason exists for smooth.
So why do Skippy and others add crap to good peanut butter? Because they unnecessarily add crap to most food products.
Skippy Peanut Butter
Peanut butter is peanut butter….. right? WRONG !!

Here is a list of ingredients in Skippy’s
ORIGINAL peanut butter direct from their website.
INGREDIENTS: ROASTED PEANUTS, SUGAR, HYDROGENATED VEGETABLE OILS (COTTONSEED, SOYBEAN AND RAPESEED) TO PREVENT SEPARATION, SALT
Here are the ingredients in their
LOW FAT version:
INGREDIENTS: ROASTED PEANUTS, CORN SYRUP SOLIDS, SUGAR, SOY PROTEIN, SALT, HYDROGENATED VEGETABLE OILS (COTTONSEED, SOYBEAN AND RAPESEED) TO PREVENT SEPARATION, MONO AND DIGLYCERIDES, MINERALS (MAGNESIUM OXIDE, ZINC OXIDE, FERRIC ORTHOPHOSPHATE, COPPER SULFATE), VITAMINS (NIACINAMIDE, PYRIDOXIDE HYDROCHLORIDE, FOLIC ADIC).
Sorry I diverge. Back to the crunchy versus smooth debate. I must be tired from the Brady versus Manning debate.