My focus with scoring systems is not using a system that purely lets teams battle for the top by climbing up and kicking other people down. My goal is letting people of comparative strength play each other, and for that a predictor gives you more accurate results than no predictor. Its a difference in goal in what we both want to obtain.
The issue I have with rung is that it essentially predicts that you loose against every team above you, and win against every team below you, as otherwise your rung is wrong. That is the basis of a rung ladder. The issue with that is that while you climb really fast teams after a while do not really settle somewhere. But continue going up and down which is why your ranking is only determined by your last match, and the team in the last match.
When you use ELO IRB Glicko TrueSkill etc, you measure someone's performance over multiple matches, allowing you to factor out differences of team performance due to averaging performances over multiple matches. Next to that with advanced systems like Glicko and TrueSkill that for instance you can take into account the inaccuracy of someone's score due to not playing for a certain time, or inaccuracy in someone's score due to never having played a match.
Although a rung based hop over system doesn't have a lot of issues with new players as if you win you simply get placed above the team you won against, without that team suddenly being worse than the other teams he previously won against. If you use the swap system then potentially the nr1 of the ladder can be swapped with the newest player in a ladder. Which is why it is more common to use a hop over rung ladder (at least if you can challenge any position above yourself) where if you win you get placed above the team you beat.
In the end its power to the people that play, that decide what system will be used, even though personally I'm not a big fan of rung based (unless its in small tiers to avoid rung based issues) but its not up to me to decide. With rung at the end of a season the score depends solely on the last match that a team that plays, rather than depending on the whole team that played matches. And that Is something I'm not a big fan off.
Since we can have different rating modules we can probably implement multiple systems as snuffel suggested and let them run next to each other (and gather statistics like which system converges faster, is the most stable and predicts the most outcomes correct), and rather than giving separate medals for every system letting the community say what they think about various systems. As discussing these things with clear facts is easier
. This should probably at the least be possible with the mathematically more easy rating systems such as various rung based systems and elo/irb based systems.
Its exactly by taking into account multiple matches, that there is a damping in the system. Which means that things such as playing with different teams won't have you hopping around extremely in rank from match to match. So you would rather end up basing someone's score based on a teams results.