Not understanding counters or how to play isn't the problem. It's actually part of the problem, as teams have figured out these defense strategies that don't generally have specific single-hero counters when you're talking about 6v6 matches.

I'm not the guy you were originally talking to, but it reads like not understanding counters is exactly the problem.

The game isn't about specific single-hero counters, it's about compositional counters. If you're attacking on Temple of Anubis and you're being locked down by a single Junk Rat then your entire team is failing to adapt to the situation.

Almost invariably the reason the attackers fail here is they're moving too slowly. You're at an immense disadvantage on the other side of the wall and your entire team needs to push through it asap. Take fast offensive characters, move through the door while the area denial characters are reloading and push around the outside.

As for trying to counter Junk Rat with specific picks any of these will achieve that to some degree:

• Pharah (Hard to hit mobile air, splash damage vs. soft char)
• Reaper (Can ghost through traps/grenade spam. Teleport right to your face)
• Genji (Reflects grenades, so fast he's impossible to hit)
• Tracer (Impossible to hit with grenades, time-rewind is OP)
• Winston (Jumps on your face, then bubbles and lasers you to death)
• Zenyatta (2 hit kill from any range + can see you through walls)
• Hanzo (Counters everyone)
• Widowmaker (1-hit kill body shot)

Junk Rat is totally ineffectual at long and short ranges and really struggles to hit fast moving or aerial characters. You don't beat him by walking slowly towards him with a shield up, you beat him by getting in his face and displacing him.