I'm assuming this is the best section to post my comments. Also apologies for any not-sense-making as I'm writing this a few minutes at a time while at work so I'm a little distracted, but I want to get this out there, at least to see if anybody else feels the way I do (though I know many people do not).

I'm posting my objection to the following addition from the latest patch, V1.0.0.139

In my experience, when people are talking to opponents in the opening minute of the game, which is not even half the time to begin with, they are usually being friendly. A friend I frequently queue with likes to "/all glhf" for example. I've seen many players who like to joke about skins and summoner names or point out that they recognize someone on the opposing team. These games are more commonly the games that don't have negative attitudes. Now with the likelihood that we've been muted by default, we are discouraged from all the above.

If there is a way to have the muting kick in after the first minute or so, it would also give the opponents a chance to reveal if they are good or bad mannered so players can at least have some information to decide if they want to disable the muting. At least if they give the friendlier players more attention they will see the community isn't all bad.

I may be one of the less cynical (more naive?) players in the game, but I think the Summoner's Code is the greatest thing for the community and the Tribunal is a great way to help enforce it. Though I consider myself thick-skinned, I can be pretty sensitive when it comes to negative attitudes. I'll usually try to be the first to discourage one player from harassing another but still, one bad attitude can ruin the entire match experience for everybody else.

Most importantly, this feature doesn't target the more damaging negative attitude that comes from within a player's own team, which almost always degrades any productive communication.

Though people seem happy about it, it isn't helping but hiding the problem of the few sour apples that spoil the bunch. People have a negative impression of the community because the people with bad attitudes are apparently not getting swift or appropriate discipline so they feel free to be horrible and rude in the next game.

As Pendragon said,
Therefore, the vast majority of opponents aren't talking enough (unfriendly) banter to warrant this.

In conclusion, (tl;dr) I think the move to make cross-team chat in all games hidden by default is generally encouraging the cynicism that perpetuates the negative attitudes but I feel a good compromise would be to make a one minute grace period when the match begins.

I love this new feature, I find the amount of BM that was in every single game was getting silly, and having to mute people every game is just annoying. I think this new feature was absolutely warranted however, I do think it should enable after 1 min, because people are friendly until someone gets fed.

I do find this unnecessary. Completely. Just mute the **** troll on the score board if you dont want to deal with it.

I'm not sure if I get your point, or if you're misinterpreting the patch notes. Yes, by default, "all" chat will be off for all summoners. Once you go into the game options, you can turn it on and it stays on until you go back in and turn it off.

Once you turn cross-team chat on, it stays on forever. You don't have to turn it on before every game, if that's what you're thinking.

fun fact.
those who care have already renabled all chat.

I've been irritated by teammates much more often than by the other team. They're in a much better position to spoil the game, and tend to feel more free to do so, in my experience.