Banning another players pick intent is justified
This is quoted directly from the Summoners Code. > While we all carry a diverse set of individual ambitions and expectations into a game of League of Legends, once we hit the Field we're a part of a team. For better or worse, our fates are intertwined with that of our teammates. Once the game gets into full swing, you have to make a choice between being a positive force for your team, or contributing to your own demise.
>** Being a good team player begins at champion select. Be open minded when considering the needs of your team. If you're the last one to pick, try to fill a niche in your team that hasn't already been filled.** If everyone's picked and something stands out as a deficiency in your team composition, try asking for another player to fill the gap, or change roles to embrace that responsibility yourself. Remember, that by taking on a role you don't normally play, you'll learn more about unfamiliar champions and increase your own skill level.