I think that the "focused on set up and customization" problem ... isn't really a problem ... if you are talking about someone relatively new to Linux (0-3 years newbies).
As Luke said, the learning of how to master one's computing environment is an enriching experience that most people don't feel the compulsion to pursue which, in my opinion, deprives them of the degree of that "sense of security" which we rely upon to trust our systems.
Beyond that, it may be considered a problem, in that, after all, a computer is meant to be a tool for productive use, not a distraction from those necessary endeavours!
I think this issue is a matter of the degree to which a person is a "perfectionist".
If one recognizes that weakness/strength, there is hope to developing the discipline to keep from getting out of control.
For me, it is a matter of recognizing when my "mania" kicks in, at which point I step back, telling myself that I need to "fence it in" by defining the objectives and scope of my "tangent offshoot", so I can return to the original task that somehow led to the discovery of the instigator for this most recent moment of mania! 
In other words, transform such events into mini-development projects, and view them that way, so that they do have, both, a start and an ending!