From a purely moral standpoint, I think refusing to pay inactive addresses is wrong. It's due payment for past work, it shouldn't be pushed back indefinitely.
No, this is dealing with Extra Credit (EC), not unpaid rewards.
Wait.. do I detect a certain sense of magnanimity in your attitude to this 'Extra Credit'?
Let's not forget that this EC is required to bring the earnings of this pool up to rough equivalency with other pools.
It's surely part of the 'reward' - just shifted in time to even out the luck.
I hope that merely by time-shifting it and terming it as 'Extra Credit' that there is not somehow a perceived lesser moral duty to pay it out??
(when (if!?) the overall pool luck eventually provides the necessary funds that is)