That is the crux of the argument. Some vegans contend that since the wasps are performing a natural function that is not being altered or forced upon them by human intervention, then it is okay to eat figs that contain wasps. Other vegans contend that eating any animal or insect parts or byproducts is inherently not vegan (like consuming honey, even if collected from a naturally occurring hive).
I am a vegetarian who eats vegan about 80% of the time, so I subscribe to a few vegan recipe and info exchange groups. There is a lot of woo and usually a bunch of pointless bickering/more-vegan-than-though-ing, but this debate is interesting, and I consider both stances valid.