I appreciate your goal of simplifying the brand strategy process, and I agree that the brand personality is very important, and can be very simple. I also agree that many fancy agencies make this process way more complex than it has to be (that is how they charge their high fees).
But, I think this process is a bit over-simplified, especially in how you talk about qualitative research. The main problem is you can’t just ask people why they buy a certain product or category, because generally they don’t really know. You’ll get rational answers and justifications of why they think they buy, but the true answer is typically more nonconscious.
Also, the “faster horse” idea is the problem, NOT what you are looking for. Henry Ford said if he had asked people what they wanted they would have said a faster horse, they couldn’t even imagine a horseless carriage (the car). This shows that consumers often can’t imagine what the future could be without some leading and stimulus to take them there.
For more on the unconscious power of brands, and how they really live in the mind, check out my book: Brand Seduction — How Neuroscience Can Help Marketers Build Memorable Brands.