Words can create a very unwelcoming environment. Riot wants to grow, or at the very least maintain their popularity for many years to come. That means they need to keep their player base active and growing. When I started this game in season 4, every single game was filled with irritating immature players who spent more time talking shit than actually playing the game. Back then I regularly had people die while typing, and then blame me for THEIR death because they were typing. Personally I like a bit of shit talk, but when the edgy kids want to pop off with slurs that they'd never say in public it gets old very quickly. As much as I think it is bullshit I can't tell a rager off, it's worth just knowing they get that immediate 14-day ban for a slur or typing "kys".
As for inters, nothing much to do but report them. As a person who used to int on my smurf (back around the time Riot cracked down) I can tell you the best way to ruin the fun is to not react. Legit makes the entire thing pointless without a reaction.