potI feel like all of these people referencing sports haven't actually played any themselves. I played on pretty much every team that my elementary, middle, and high schools had to offer and I never once got shit talked nor did I shit talk anyone myself. Just because you're being competitive doesn't mean you suddenly forget how to conduct yourself in public. Even in university now I've never experienced shit-talk.
Shit talk happens all the time in sports, and esports as well.
Example
I played hockey, soccer, lacrosse growing up and have experienced shit talking in all settings, whether it be at a high level or in a houseleague game. I've even experienced it in a pickup game at university. It's a tactic which may be frowned upon, but if you can get into your opponents head and mess their game up, why wouldn't you use it?
Yeah you're playing in front of potential sponsors and ESEA, however you can't seriously tell me that the CS:GO, LoL or any other competitive gamers never used slurs before.