I don't understand the point of this comment. No one is saying that 3D printing will make forging obsolete. There's always a balance of trade offs. It's up to the designer/engineer to decide how something should be made. Developing more options, and better understanding those options is part of engineering progress. It may be good to temper expectations (no pun intended) to avoid overhype, but at the same time I think it's also good to let people's imaginations run wild because that's where creative developments come from.

For example, I'm sure people will come up with ways to have more control over grain boundary and other material properties of the 3D printed material through the use of heated chambers, annealing, new alloys created for specific processes, etc.