As I've said before I play quite a bit of PvP, just never BA as apparently it's pretty dead on PC so haven't tried it (I do want to though), it's all TT and the weekly events as they pop pretty much instantly when I normally play. I have played many other shooters where PvP was the only mode available going back to the old days with no mouse look and of course our favorite controller based shooter; Goldeneye on the N64 (although it's only on the console before they connected to the internet so it doesn't really count since it was friends only). I've seen all kinds of garbage plays and terrible teammates, people exploiting terrain, using costumes or skins that let them blend in or are glitched to a certain degree that provides an advantage and so on.
When BA goes ranked, I expect it to get MUCH worse. Clan Wars in WoT made regular matches look like lovefests and I used to turn my chat off in those pick up games after getting all kinds of lovely messages from people that include various degrees of self-harm so you can imagine how bad those could get.
For BfN, the worst I saw was in Zack Scott's video where he kept getting targeted by a couple of people that always taunted after they vanquished him. I loathe that kind of behavior and anyone that needs to exploit mechanics to win needs to reevaluate their life choices.
Wolfy and Zero get targeted a lot in both GW games and some in BfN too. I have been targeted in all 3 games but when it gets bad I will likely switch to a different character/variant to confuse them, and so far it's only been as Wizard in BfN or if it was happening elsewhere, I was able to smack the other person enough that I didn't notice.
To be honest, considering the nasty messages I see console players show that they receive, it sounds like the console community is significantly worse than the PC crowd is. I have 3200 hours between the 3 games and a large chunk is PvP, especially in GW1 that lacked bot matches and real solo play, and I rarely see the same behavior I've seen in OW, WoT, and some of the stuff console players have linked from the messaging service that the modern consoles have.