Stuck in a Rut ?

As mentioned in earlier posts, I have a strong historic background in development, but recently I have been trying to be more Project Management focused.

I see Project Management as a broad topic which encompasses many aspects such as team/morale building, time/risk/issue management, stakeholder management, project progress, milestones, reporting etc... all which boil down to good communication.

Therefore, my "gripe" for today is... why does it matter what technology you are running a project for? 

Usually there is a Chief Architect to aid the project manager in the more technical side of things. The Project Manager tends to open doors and look to the future to make sure everything is in place (or will be in place) for when it is required further down the project time line.... so why do we need specific skills in technology to be a good project manager. I do understand that you must have a basic understanding of the technology being used (as an IT Project Manager), but I do not see why you need to have the full blown technical knowledge.

I only moan, purely because I have been a Lotus Notes man for many years (and, yes, I do LOVE the product), but many of the roles I am trying to go for require an understanding of other specific technologies.  

Surely the sign of a good PM is one that can run with anything and pick up failing projects and bring them into line. For this, I do not think you need a complete understanding of specifics.

... or am I going to be forever, Stuck in a Rut with Lotus Notes?