yeah thats easier or you can just play normals. u dont have to play ranked.
to answer your question, yes. every game that has a very competitive ranked ladder comes with people who get very upset when they are losing. its just natural, it has nothing to do with the game specifically. people are like that in other games like overwatch and csgo. LoL just has a lot of people so you see it more often. you have to realize though that there are a ton of people who aren't crazily toxic as well. its a part of playing competitive team video games that you have to deal with teammates