I also don't need to have any additional ingredients in soap. A lot of colorants are not anything I would want to have on myself or in my septic system. I'm sure you'll use something that's not terrible, but I just don't see the point on a consumable item that is just going to add expense.
Discussion
That's why I have the plain, unscented Tallow brother. For ppl that don't want it. Most ppl enjoy colors and scents.