You're trying to overcomplicate things for no reason. DPS is the damage you did, per second. It's literally all you need to know about your contribution to the fight. PPS is unreliable as it doesn't take into account the crits, the party buffs, the direct hits or anything else that has real fight applications.

There is no need for any other calculation as we already have one that works as intended, trying to change it or suggest another on top of that is a classic case of fixing something that isn't broken in the first place.