The actual problem about vanilla is that 2 groups are forced into the same system. Casual PvPers have to face competetive PvPers.
For competetive players its a drag since you often just steamroll the opposing team.
For casual players is a drag since you often get, you guessed it, steamrolled.
Compare this to other games where you have ranked and unranked matchmaking.
1 side will get frustrated if they get too little competition and the other side will get frustrated if they get force fed dick in every game they join.