We are all very good at tunneling. In BG’s epic battles can be waged around control over an uncapped node involving half the players from both sides.
When you take a breath, and look up at the scoreboard, the other team has managed to cap 3 nodes, and you only have stables. The fight over this one uncapped node has distracted your team that much that enough time has passed for the other side to get a decent lead.
The healers could be merrily healing away – you get into this zone watching green health bars, throw a fear out in your hit capped healing set so all your fears don’t fail. La la laaaa la di dah, Bubble, flash, renew, Penance on a bad one, heal them up, more bubbles, oh look barriers up, fear, holy nova to stop that sneaky rogue cap. La di dahhhh
Then you realize its been going on too long and the dps your healing aren’t targeting their healers
[Battleground] [ Z] Kill the healers!
[Battleground] [Z] Target their healers!
La di dah…
So at this point, you’re getting ok Hk’s and your healing is looking awesome on the meters ( because the other team is not targeting you either.) Technically you are doing your job. You’re healing. No one is complaining about your healing, people are staying alive. What else are you supposed to do?
Walk away?
/scoff
But if you walk away they will all die, and so will you most likely once that me hunter you prey instinct kicks in and the enemy team go ” look squishy trying to run away kill kill kill !”
Z dies
But so do the rest of the people you’re healing at an unsuccessful node cap and by that point your team now has to come back from a 3 -4 node cap.
People who fight on the roads, will stay on that road if there is a healer enabling them to fight. It’s a hard thing to do, to ride past that person with half a health bar.
So yes, walking away could be the best thing you do, to enable your team to refocus because as long as they are staying alive, they will just keep tunneling
Provided by 
Pugnacious Priest's Warcraft Blog 
Actually I do walk away now and then:) Especially from stables. A horde defended stables can easily hold up 8 alliance if they are on the ball. Its just a waste of time. But the other 99% of the time? So true.
This is so true! I was going to do a post about tunnel vision in BGs and this gives me food for thought.
The walkaway thing is actually more dependant on the size of the confrontation and location relative to objectives.
If your team is fighting in a big zerg blob and has met another zerg blob as a healer you shouldn’t walk away even if you are fighting on the arathi bridge. Assuming there is still someone near the flag the result of losing a zerg can result in multiple flag captures.
The people you want to walkaway from is the 1-2 guys who go charging after that guy on a mount who isn’t anywhere near a base. There are rare exceptions to that rule depending again on how the fight is currently going in certain locations and the class/ skill of the pvper you are dealing with. If for example someone attacked a class with high survivability that would prevent you from capping a nearby flag it is best to help the guy kill him and carry on.
It is also important to pay attention to suicides aimed at preventing the full power of a zerg from steamrolling a node on respawn. That hunter who went running in spamming three different traps while shooting concusive shots or a priest who is going to fear spam them is usually screwed even though their tactic is successful.