Since most game are 80% complete, it seems that nobody has the dedication to push the line further, but a perfectionnist person or somebody with obsessive compulsive disorder would push that line further by making sure everything is "Perfect" (to his point of view).
Now in every day live, it's not a necessity to be perfectionnist it can actually be annoying, but in board game design, would it worth it to have taken into account every detail possible the designer can percieve.
As a library technician, I often say that a part of my job could be renamed "detail management" as for example I need to use 1100 page rule book for cataloguing (the newer version has more). Maybe this is one of the reason I am so much obsessed with detail.
I wrote an article about this some time ago according to a book that I read that had that following citation:
"Making an 80% game is very easy. A lot of games out there are just 80% finished. With more testing the game could be more elegant and the last 20% takes a lot of time. That's the difficult part. - Reiner Knizia "
The article can be found here:
http://bgd.lariennalibrary.com/index.php?n=DesignArticle.Article-Incompl...
80% can also be based on pareto's law.
Most game designer stop their design too soon when they get a game in working state. But a perfectionnist is less likely to stop there because he wants everything to be perfect (which is of course unchievable) but it is still better to try achieving perfection than not trying at all.
When designing as a team, that is another issue. I imagine for video game design, if the art designer is obssessed, it will reach as far as the art department. But in video game design, the real limit will be money available for the project.