It sounds like what people want is a measure that reflects present ability.

A K|D ratio for the most recent (N) kills and deaths, and K|D totals for the most recent (T) hours of game play would accomplish that.

If you have a measure that reflects the present ability of a player, judging them based on their cumulative stats is pointless. For that reason if such a measure is implemented, it's trivial to include overall deaths in stats because they don't matter compared to present ability.