This is a question that should be asked because I thinkn there is a mis-conception in the minds of many project managers as to what their role is.
In my experience which began being a project manager before the term was even used, there are two fundamental requirements.
The first is an understanding of the processes required to complete the project. I am speakng about the actual work flow that must go into the project. Most recently I was employed by a software firm to manage implementation project. Coming from a hardware services setting, I needed to understand the process of the implementation n order to create the schedule and converse wth my clents as to this process.
The reality point is to understand that the process and all the related paperwork, graphs, etc. are only means to acheve the end. This is where the actual management of the project comes into play. I have seen too many project managers who are deficient in management skills. My perception here comes from my function as a PM who has often worked more as a general contractor in projects requiring personnel, equipment and services from multiple vendors. Here is where I find that the management skills are lacking.
So the Project Manager is very important. I have used my skills here in areas other than telecommunications and they work.