For someone who's in the business I can easily see how buying a commercial rub would save on time and also keep some form of consistency with the product.
That is probably the best way. We've always said that BBQ restaurants do not have the time to cater to each individual cut of meat like the backyard warrior does. They are serving a mass amount of people within a small window of time. So they cannot afford to waste time, money or hit and miss on consistency.