Clarification on D.

[aberba via Digitalmars-d]

I don't really have much experience with large code base, so 
spare me.

 From a technical and experience point of view (those with 
experience in large D code-base), how is only D's GC & optional 
MMM a significant production-use blocker?

  (To make my problem clear, how is D's current state not going to 
allow / make it so difficult for developers (who know what they 
are doing) to write say Photoshop-scale software: excluding those 
*so* realtime use cases?)

Note: I understand that D is never going without critics: 
perfection is impossible. And, in my line of work, I highly 
prefer the safety of GC compared to MMM... so I don't see myself 
worried about GC pauses.

I hope my question makes sense.