Depends on the tank. WAR and GNB die pretty easily, especially WAR. If you can catch a PLD off guard then absolutely kill them, but the problem is if you don't get the kill people just keep attacking them which is just like....why, please stop lol. Same with DRK. People get thirsty and see DRK at 1% but don't realize they are using living dead and waste globals on the DRK.

But in general yes its probably better to ignore the tank and kill the backline. People just lose sight of that because the tank is always in the front and a lot of people don't want to dive the back line and if you have a ton of ranged the ranged is gonna wanna stay back so the tank is their only target.