When we think of "battle," we think of the ancient art of warfare in all its glory and blood shed.
You can imagine warriors on armored horseback, with a shield, a long sword, arrows or a war club. They would charge directly into the enemy's lines without fear or hesitation. Soldiers are trained to do only one thing: kill or be killed.
In LOST, when we were told of an impending "battle," we got a wet noodle fire work at best.
After Jacob was slain by Ben, the remainder of the followers were in panic. The statement that gave them great pause, "they are coming!"
Now, in the imaginative circles of the LOST community, this was supposed to be a brilliant "whoa" right story angle of monumental proportions. At the time I wrote that I thought it would be cool that above the Tawaret statue would rise the silhouettes of men carrying spears. Then there would be a huge loud cracking scream from above, and the men above would suddenly sprout black wings. These would be Hell's soldiers returning to the island to reek havoc, since a central theme of the series was good vs. evil.
But alas, nothing as out-there or big as Hell's warriors coming to the island. There would be no pitched battles, hand to hand combat, or a reason why the island was under attack.
Who was coming - - - was another vague threat to raise dramatic tension.
Widmore? His men had already been on the island.
Jacob's reserves? The followers left in the Temple were wiped out by Flocke/Smoke Monster.
Jack and the Candidates? They were not organized to do anything, let alone fight against an unknown foe.
For if the one key battle was that of Jacob against MIB, then MIB won when Ben betrayed his master. But somehow, that did not stop Flocke's continued quest to kill off all the candidates, who still did not know their true purpose on the island.
For if the battles were more symbolic, mind games, then the resolution of daddy-issues, accountability, fear of loneliness or mental illness was anti-climatic.
I think somehow we are still owed a "battle" by TPTB.
Yes, there was a lot of red shirts in the struggles between the survivors and the Others, but those incidents really had little basis in true conflict. The Others claimed the island as their own, but did nothing to remove the survivors from it. The truce was created because the survivors lacked a killer streak, and Ben found it more useful to mentally manipulate the new castaways then to kill them all off.
No a real battle has to resolve real issues, like territory, property or even for a cause. None of those things were present in the characters final motivations. The heart of the island was unknown to them except for Desmond, Hurley and Jack at the end. Kate, Sawyer, Claire, and the rest were not fighting to protect mankind or the heart of the island from evil; they had no idea that it existed or what MIB was trying to accomplish by controlling it.
The build up of a battle without an actual battle was quite disappointing, and most fans do not dwell on it because the story rushed to an even more uneven ending arc.