Assume that a brand idea is subconsciously shortened and simplified in a consumer's mind. While you may think your brand is complex, your audience likely simplifies your brand to a single idea - a notion so focused that the brand itself can be symbolized in a single word.
Ideally, a brand strategically determines the word they hope to "own" in the consumer's mind. They find the single concept of value that differentiates the brand and defines what consumers value most.
If consumers are not able to shorten a brand's purpose in an instant, it gets filed under ... "I don't know". When your brand's value is nebulous, consumers will come up with their own easily digestible idea. This scenario might obstruct the purchase decision a consumer is ready to make right now.