When your teammates too proud of themselves only attacking ADC & APC

So this was in ARAM. Sona dive in 1v3 with 80% hp only to kill one ADC with low hp. Die herself afterwards and we were aced. She complained that I keep attacking Leona with my Kayle. I did not keep attacking her. I still tried to reach to enemy AP and AD when possible, but I had to get Leona's attention on me, so my teammates can focus on the AD and AP. Our tank Singed has been AFK every once in a while so we lost team fight because of 4v5. But then they blame on me because I tried to get Leona. They probably didn't realize how they end up being able to attack enemy AD and AP at the first place. Leona has so many cc they can be harassed to death without even reach anyone on the back. It's funny how people are so proud of following principles but neglect to look at the actual circumstances. It turned out both our Sona and Zilean blamed on me, but in fact I never saw Sona making good use of her passive with Q+A combo, and Zilean didn't even know he could cast ult on himself by alt+R. Guess I shouldn't be upset since I was really just blamed by newbies. Oh! And I never saw Sona's ult throughout the game.