Well first of all, if my behavior is not up to your standards then you can just choose to mute me. Secondly, you get reported for anything in League.
It's not about your behavior not being up to any given player's standards - it's about your behavior not being up to Riot's standards. While competitive BM'ing is allowed, trash-talking isn't. Trash talking is just plain spiteful, negative, and nobody wants to deal with it.
The difference between competitive BM and trash-talking is that the former is biting, but still light-hearted - a playful jab to aggravate opponents without just plain harassing them - while the latter is blatant harassment and negativity with no other purpose than to spew hate at your opponent.
Calling someone "trash" or "garbage" or "shit", or bringing up Rank as a way to shame someone is trash talking.
Getting called bad after killing someone and responding with something like "if I'm bad, what does that make you?" - that's competitive BM.
And, more importantly, there's something else that needs to be addressed; competitive BM can cross over into the realm of trash talk. If all you do is throw out quips about how the enemy team sucks or how you just wrecked them, then, guess what - you're now trash-talking. Moderation is necessary.
Throwing out a small, biting remark to highlight a play or a win every now and again is one thing, but doing it every other minute is just plain bad sportsmanship.
I like to trashtalk when I play, it makes the competitive side of the game more fun for me.
Again; trash talk is not welcome. Even competitive BM'ing is moderately frowned upon, since it can very easily devolve into trash-talk. And nobody likes trash talk.
And, one of the rules of League of Legends is: "Enjoy yourself, but not at anyone's expense". So, if the community says trash-talking isn't allowed, and trash-talking is something that you enjoy...Well, you have to find something else.
If people don't want in on it they can mute me very easily and I would not have a problem with that.
And people would still ultimately have a problem with you for spouting negativity regardless of if they muted you or not. Hence;
Players report me for this, I lose honor levels.
Besides, in this mode my friends have already decided that I'm honorable enough to play with lol. They don't need Riot to make that decision for them.
Pardon, did your friends make League of Legends? Did they set all the rules up? No? Then it's not their place to decide if you're honorable enough for competitive tournaments.
This is Riot's game, and it's their decision that players below Honor Level 2 don't get to play in Tournament mode. Your friends have no say in that.