While a talented and motivated individual can indeed create a lot of value, this will inevitably also create a lot of dependency on said person. Now this person has become a liability, and HR doesn't like liabilities.
Not exactly. I do agreed about the value destroying part. But unless the knowledge mentioned is standardized, it's not really easy to transfer them to the succeeding team members.
Some highly successful products (or features in these products) was created because the effort from one or two employees who got the idea based on their knowledge from life. Without these key employees, the product/features will never be implemented, and the success will never happen (and nobody will know it's possible).
It's the same way how CEO/CTO works, really. Some CEO lead the company to success while others failed, not because they're incompetent, but because the knowledge is not there, which lead to (for example) the lack of imagination and growth.
But unlike the leaders, employees usually don't receive nearly enough reward for their insight, if their effort is noticed at all. That's the dilemma.