I'm guessing that wargamers as a group have a terrible ratio between number of games owned and number of times played. I myself own just a few wargames, and they rarely ever get played, for the following reasons:
1. Most wargames are two-player. If I'm in the mood to play games, I'm generally looking for a more social gathering of at least four people.
2. Rules tend to be complex, making for a steep learning curve.
3. Games are long, making for fewer opportunities to play.
4. All of the above makes for a tough sell to a potential opponent unless they specifically are interested in a given wargame under discussion.
So it seems to me that maybe wargamers are more likely to be collecting games than playing them, whether intentionally or not.