Sure, but I wasn't suggesting people never grow, just that there are those who never brew the same thing twice. My sense is that most of those--I'm allowing for exceptions--are afraid to find out they can't, and the way to avoid that realization is to never try.
I think the only way you can really assess your process is that last part--if you can't make it taste the same, then you have variance in your process, and for me, that's not good. Others may not care. And in fairness, different people may have different goals. I want to brew the best beer possible and I don't see how I can figure that out if I'm not trying to repeat recipes. I don't have to brew them 10 times before determining that--in fact, if I can repeat maybe 3 or 4 recipes, then I'm showing my process is consistent.
This is why I think that's important: before I start changing things, I had better be sure the changes are intentional ones to either the recipe or the process, and not some random difference from batch to batch. If you can't brew consistent batches, there is no way to determine whether a change, good or bad, comes from intentional alteration or some random thing.
I agree, if it tastes good, it's good. But if you can't reproduce it....and frankly I suspect some of that "it's good" stuff may be confirmation bias, not true quality.
But in the end, people have the right to choose their own goals. They don't have to do what I do, nor I do what they do. If they enjoy the process, that's the only thing that really matters.