Interesting discussion on ratings and how to manage it.
In terms of overall stats - I'm sure if you ask people care more for their win/loss ratio and not for points. An inactivity point deduction or actually a points reset would be fine - just archive people's win/loss stats.
That way people won't be demotivated about having less points and can have a "current climate number 1 status" and those who have played in the past still have a record/history to show.