I love all aspects of BBQ; to me, when I serve up my Q, which is rubbed with my rub, smoked with wood I harvested, and served with a sauce or two (on the side) of my own creation... there's no better feeling. I love to see the plates come back looking like they've been licked clean.
I got swamped one day a few years ago with all kinds of non-cooking stuff (business), that I didn't have time to do a proper (in my mind) sauce. I grabbed a jug of Head Country (which is pretty damned good sauce) and served that instead. People commented that my sauce wasn't quite what they have come to expect.
Yes, you can use commercial sauces, nothing wrong with that at all. It's up to each individual cook what they want to do. Me? I enjoy the process of making the sauce. Inventing a new one is even more fun!