Changes.

Project delivery has changed.  It used to be that projects were completed by large in-house teams who had been with the company or government entity for many years.  Junior members in this team environment had consistent and informed expertise above them to learn from and progress with. 

Organisational changes have resulted in outsourcing, reduced middle management, just-in-time hiring, shrinking training budgets, and little scope for on-the-job training of new and not-so-new personnel. 

Outsourcing and privatisation (shareholder focus) have demolished this critical aspect of infrastructure development and management:   consistent and repetitive exposure to someone more experienced, which naturally leads to learning.