The way the current Elo system has been implemented is flawed. Normally an Elo system assumes there is equal probability of winning given an identical Elo rating. Because there is a bias towards town winning and there are more town roles, this assumption is violated. This has the effect of making the rating system reflect number of games played, rather than actual skill level (It's relatively easy to demonstrate this empirically). Basically more games = higher rating.
If the idea is to have some feel good measure to make people play more to achieve a higher score that's fine, but perhaps could you offer two game modes?; one for people who want to play with others of a similar skill and another for people who want to see an arbitrary number go up by playing more games.