There's nothing wrong about focusing the tank
If tanks initiate without quick followup, you should have no problem bursting a tank in under 2 seconds with 5 people unless the tank has 6 items and everybody on your team sold all of theirs.
4 Comments
It's typically the adc's job to do so, but if the rest of the team isn't there then... well, that's a free kill.
A tank wants to be focused and be the only one to die if need be... but only if, ya know, he's/she's drawing focus away from someone else like the carries.
The problem is when your AP mid blows all their cooldowns on the tank to kill it, then has nothing for the rest of the team. Or they fail to shift their focus when better targets jump in because the tank is at <50%.
That makes sense if it's 5v1, but assuming a 5v5 matchup if you're focusing the tank instead of the carries you're doing it wrong.