"Dun focus duh tanks!"
It is really unusual for me to want to punch people in the face, but, after hearing this as often as I do, it's getting to the point where I really do wish I were there to punch people in the face when they say it.
Obviously, if you have an equally good shot at a tank and a squishy carry, you're not going to waste it on the tank. But, if you're dying over and over again while you try to dive past tanks to get to those squishies you'd rather be focusing, maybe it's time to re-evaluate your strategy rather than blaming the people on your team who are at least trying to distract them and bait out their abilities for violating your mantra about not focusing tanks (And let's not even get into how we might even be able to take out one of those tanks pretty quickly if we all work together, leaving the enemies' carries much more open to your diving heroics once he's out of the way - this would blow way too many people's minds.)