Whenever you play a matchmaker game (1v1, 2v2, etc) and the game is rated, the rating system will perform an additional rating step using players global rating. This works by taking the matchmaker ratings of all players, substituting in the global rating for the player who's rating is being adjusted. The changes to global are then applied to players that meet a few conditions:
The player's global rating must be below a threshold (currently 1400)
The player's matchmaker rating must be higher than the player's global rating
The global rating change must result in an increase in displayed rating
Any players who don't meet all of those conditions will not have their global rating changed by the game.
This proposed idea is heavily flawed, and I don't think it should be implemented in this manner.
Afaik, the rating system is currently a zero sum game*. If the idea proposed above is implemented, FAF would have perpetual global rating inflation; it would no longer be a zero sum game. That seems like a very bad change to make, especially when there are alternative ways to address the issues regarding new players.
So, I propose that we implement an alternative solution:
One alternative solution would be to change the above proposal to specifically affect rating sigma but not rating mu. The conditions for when it would apply could be the same, and the value to change sigma by could be calculated in whatever way seems most sensible (such as changing sigma by an amount that would result in the same change in displayed rating as you would get via normal rating calculations). This would avoid perpetual rating inflation, as players' base ratings would remain the same, while grays' displayed ratings and rating certainty could increase (if the conditions are met) towards the proposed 1400 rating threshold.
Another alternative solution would be to create a universal rating that is affected by all rated normal game types on ladder, TMM, and global, and display that (perhaps in a different color, such as gold) in lieu of global for players with high rating uncertainty (grays).
I think this thread is a great example of why having development discussions on the forums is not useful. There is a ton of text here and a lot of rage but not very much that is actually productive.
This might be a complicated topic, but that doesn't mean it shouldn't be discussed by more of the community than the particular developers/etc who happened to look over the relevant commits on github/etc.
In fact, there are several other alternative solutions (beyond my suggestions and the basic idea of just applying regular global rating calculations to ladder/TMM games for all players) that potentially could be suggested/considered/discussed as well. There is no reason we can't have transparency and useful community discussion on this.
*Yes, you can make the argument that players permanently quitting adds rating inflation/deflation. Regardless, the proposed change detailed in Askaholic's post would add further perpetual global rating inflation on top of whatever we may or may not already have. So, increasing inflation is still something that would be good to avoid.