Toxic players in bot games

I occasionally play bot games when if my internet is being laggy or Im farming on my mobile game. Theres some people that seem to only play bots, and they have hundreds of games and they take it super seriously!!!

I had this one guy (his name was like mattx0123) call "adc" in champ select, some other guy locks in Vayne. Matt says "fk u vayne", but he locks in as Nautilus. Because we cant have 2 ADCs and must have a support in bots right?

Im on Kindred and I have Teleport/Smite, but Im not jungling, I just have it because I dont need flash for bots. Our Vayne never says anything and goes mid. I go bot with my Smite and a Volibear. Matt says "wtf r u doin kindred go jungle" "vayn go bot r u retard?????" Im amused but I ignore this guy along with everyone else. Matt ends up going top.

Vayne starts off 0/3, and Matt is spamming pings at him and says "dont go mid then feed u useless trash". I farm enough gold for vamp scepter, then I go afk farm the jungle while pulling double duty farming on my mobile game. Ive been afk farming for like 10 minutes and of course this leaves Volibear bot 1v2 and hes like 0/6 and loses both towers. The bots are still pushing and Matt is spamming pings at bot and me telling me to help. He says hes going to report me for not helping the team. Then, he types in all chat. HE TYPED IN ALL CHAT IN A BOT GAME. "enjoy free win cuz of kindred" At this point my patience is tried and I tell him to stop being toxic, and to be nice to the Vayne who is clearly a new player. I ask him why hes typing in all chat in a bot game and he calls me an "idiot" and says "what r u gonna do about it???".

At this point I have gold for items and I set down my mobile game and proceed to 1v5 the enemy team and push to win, along with Matt accusing me of "ks" several times and also making sure to remind the Vayne and Volibear how bad they were (they ended 0/9 and 0/10). This guy had over a thousand wins in bots and was clearly a "bot game main".

This isnt the first time Ive encountered this behavior in bots. Ive gotten reported by a premade (yeah a premade) for "trolling" by going mid with an ADC. What drives people to act this way? Why are they so rude to new players? Why would any new player want to play this game if this is the kind of experience they get?