Junkrat wrecks turret based heroes with his concussion mine at close range, Widowmaker wrecks them at long range. Genji and Zarya can both turn turrets from a strength into a weakness (especially the dwarf's turrets which can't stop firing); bonus points for Zarya being able to attack turrets from outside LoS.
A lot of what makes Bastion and the dwarf so good on defense is that people aren't determined enough about suppressing Reinhardt's shield. If you just keep firing he *has* to drop it eventually.
The rule of thumb in MOBAs is unless you read guides and watch professional videos. You stink (And I have NO idea if I am joking or not)
I'll help you: you're joking. Overwatch is about where TF2 is in terms of learnability. Its pick up and play with a high skill ceiling. Only difference is that Overwatch has more classes, which individually have less to learn. On the other hand Overwatch is far more oriented towards competitive play (compare TF2 where yes there's a high skill ceiling but you have to remove 80% of the game's content to play competitively).
It's not that he's joking, it's that Neonivek lives in a different universe where things don't work the way they do here, so all of his posts come through to our universe not making any sense.
Bastion's problem is that he scales with the enemy team. You might know how to deal with him, but if the other five people on your team don't he's gonna roll all over you and there's not much you can do about it aside from becoming a dedicated anti-bastion. Which can work.
The other problem is that all of his "counters" don't actually counter him. Genji can use E. Neat. Bastion can just not shoot for two seconds, then kill him instantly. That's not a counter. Bastion has a bunch of soft counters with correct play, but the only two real "hard" counters for him are Reinhardt with concentrated fire behind him, or an offense going deep and catching him while he's walking back from spawn.
He kills all the counters listed handily if they misplay even slightly. All the offense counters die instantly if they can't kill him before he knows what's happening. Pharah can get him but she has to expose herself for it. Again, only if you catch him by surprise and kill him immediately.
Bastion isn't good by any stretch of the word. But he's fucking infuriating to play against and even when I'm making him useless I hate him.
It's multiplayer. It's online. It's a battle. It's an arena. By that logic though quake is a moba. Tell quake fans it's a moba, that should be funny.