Because while you may seek to use it for the purpose it's originally designed (communicate with your team), others don't.
More players like you pls
It's fair to be able to expect a harassment free environment when you're playing a Video Game, and chat functions can sometimes provide places where this can occur.
Your point is fair. Characters in our game Swear, and the content is openly violent. It carries appropriate age ratings in different countries all over the world and is compliant with different authorities and regulatory bodies.
I can understand that in certain circumstances, it may clash with what the game is, and who's expected to play it. As an adult, I don't have a problem with swearing and I swear pretty liberally myself, often in place of punctuation.
'Good f*cking game lads that was close!'
'sh*t the bed what the f*ck was that?'
'I just got f*cking ruined by that tank, careful'
The challenge is that unless we have very sophisticated machine learning in place to identify when bad words are being used in a non-threatening/non harassment manner, there's a risk that words are used in a way that's directly aggressive to other individuals, and all our experience dealing with Toxic players informs us that targeted forms of aggressive behaviour (100% against our TOS) often feature this language. It's why Swear Words will often feature in blocked word lists, because it helps to reduce instances of toxic behaviour.
Does that eliminate harassment? No. Does that stop people from harassing people without triggering blocked word lists? No. Should that stop us from implementing changes to address that? No.
I'll also volunteer that blocking words isn't the only way that this should be pursued. There are other design considerations we can make in future titles that change the experience here (and I encourage you to share what you would like to see change in this area across our industry). Naturally we need to continue working through the reports provided to us by players to remove players after the incident has occurred and prevent them from returning to the game if they refuse to play by the rules.
Relative to this change, it's helping to address an issue with an existing function in the game. It's a recent and new change, and it'll need adjustment - I'm grateful for anyone here in the post who can help to share examples that I can provide to the team managing this new function, and I apologise for the short term disruptions it may cause.
Back to the rest, this is a big topic, with lots that needs to be considered. As a person I have loads of different views on the matter that change game to game and platform to platform - with my central, personal view being that people shouldn't be exposed to toxic behaviour and that our industry can be more pro-active in the area. You'll have views too, please do share them (I'm personally interested in hearing as many views as possible).
As a company, we've spoken about it here if you're interested in what EA are doing to address it - https://www.ea.com/en-gb/news/reporting-tools