It must've been terrible for Thranduil to watch his immortal kin lie dead on the ground, after fighting for people who were destined to in a few decades die of old age either way. In that way I can understand why he wanted to leave the battle. But I agree with Tauriel also - it was a fight the dwarves couldn't have won without the help of the elves (and the eagles, of course, but that was Radagast's and Gandalf's doing).
![](https://i.ytimg.com/vi/H_cMzt5HgM4/mqdefault.jpg)