HR's role in talent management

What should be HR's role in ensuring that talent management is effective, and how well are we performing in it?
In Management Consultant International, Kennedy are upbeat, finding that HR has been successful in gaining executive attention for talent management and pointing to 'a current trend of elevating the role of human resource professionals'.

This is unfortunately not what McKinsey have found:

'Our research confirms the idea that HR's influence is declining. The executives we interviewed criticised HR professionals for lacking business knowledge, observing that many of them working in a narrow administrative way rather than addressing long-term issues such as talent strategy and workforce planning (see graph). As one HR Director explained, senior executives "don't see us as having business knowledge to provide any valuable insights. We're doing many things based on requests, and they don't see HR as a profession." '

According to McKinsey, 58% of all line managers believe that the HR function lacks the wherewithal to develop talent strategies in line with a company's business objectives!

The need is that:

'Human resources should asset its influence over business strategy, and provide credible and proactive counsel and support for the chiefs and line managers of individual business units. Only HR can translate a business strategy into a detailed talent strategy: for instance, how many people does the company need in order to execute its business strategy, where does it need them, and what skills should they have?'

I don't really understand why we're not doing this. What are we waiting for?