In mmo's like wow, you have a choice of teammates and if you don't like who you are playing with, you can choose not to group with them. As a result, the people you end up playing with are comfortable with your communications. If someone doesn't like the way you talk to them, you will likely never play with them again. All you need is to find a half dozen people you enjoy playing with and you never have to worry about random teammates.
In league, you don't have that option, so you can't make the assumption that everyone is ok with being called a degenerate or whatever words you choose to use. If you don't know, talk to people the way you would meeting a stranger for the first time.
I dont get easily offended, but I'm also not good and need to focus on what I'm doing. Making me have look at the chat just to find name calling and criticism...directed at me or not takes my attention away from playing and makes me play worse. More than a couple comments like that will get a report because its reducing my ability to play at me best.
Calling out mistakes is useless and tilting to me. Most of the time I know I screwed up. Having one or more people that feel the need to point it out is just throwing salt in the wound. Knowing how I need to adjust my play to fix the outcome or prevent it from happening might be useful IF AND ONLY IF it can be applied immediately, but I only occasionally get that......"farm better...." does nothing in game.