In the end we use what works best for us, what suits our tastes, preferences, and what time allows us to do.
It doesn't mean it's right for everyone to buy commercially rubs. Some will, some won't.
The bottom line is that making multi-layers of flavors in rubs at home is not an easy task. I takes time to order fresh ingredients, properly measure and mix them to get that product you are seeking. To many of us time is an important commodity, much like money. Just as we spend our money wisely, many of us have to manage our time with the same principals. Some of us have the time and others do not, in the end we do what is best for our individual needs.
The nature of my post was to explain that after 10 years of mixing my own rubs, I no longer had the time to make my own, so settled on one commercial rub which was great. After 5 -6 years of using this great rub, I let my guard down and tried a different rub for a family gathering. To my surprise, this exceeded the expectations of my regular rub. I wish I had experimented and tried other commercial rubs years ago. But with a closed mindset I had skipped by one of the best rubs I have ever tried.
Some of us make rubs to save money, some are happy with basics like salt and pepper. That's all fine and dandy, nothing wrong with that. I too, at one time, felt this way. I felt smaller bottles of rubs were just too expensive. It wasn't until my small cooks grew into catering events that I found that I did not have the time needed to order and mix the rubs. That's when I began using a commercial rub.
I'll be the first to say that I am as cheap as the day is long, but I also feel that you get what you pay for. Somewhere in the middle is a balance that we all adhere to, but at different levels of compliance.
My post here was probably geared to the newer users, telling them not to be afraid to try a commercial rub. Granted some are great and some are far from it, regional and personal tastes are the greatest variables between our own individual choices. The other factor is how the individual uses the rub. Some lightly sprinkle the rub on, others (like myself) dredge the meat into the rub, this too affects the final flavor of the meat.
Also not all commercial rubs are created equal... I have used some that appear to be all salt, others have high sugar content. These may be a desired flavor profile for some, but not for me. I feel these manufacturers who use too much salt or sugar are using these as fillers trying to get a larger return to gain larger profits.
Then again there may be consistency issues with some rubs. I had tried a different commercial rub many years ago, the first two cases I used were great, the third case was overly salty. When I contacted the team about the issue they never responded, so in a pinch I found a local team who sold a rub with absolute consistency.
In the end, I am saying to open your mind to other things. I was set in my ways and my train of thought. I could have saved myself 10 years of ordering and mixing in an effort trying to achieve what was already available to me. However if you find one you really like, then try to replicate it if you are so inclined to mix your own rubs.
Making rubs or buying rubs will always be a personal choice. Doing either does not make your "Q" better or worse. Either can expand your flavor horizons and help you find the apex of your cooks. Not everyone cooks in large volumes and buying in bulk can be a bad choice if they have small cooks.
Rubs are like tools, a good design can help make the "BBQ" great, while others may not, use your tools properly. Think of using a pair of pliers to remove a screw, it'll get the job done, but not as good and effectively as the proper screwdriver.