Power
In this career, it's all about perception.
When you're assessing a damaged or destroyed piece of property, the claimant is going to view you as a pretty powerful person. After all, you're the one with the iPad or the laptop; you're busily making notes, asking questions, taking photos, and putting all the pieces together for your report. You're the face of the insurance company to the claimant and you'll be the one delivering the "yes" or "no" answer that will ultimately impact (positively or negatively) the claimant's life, psyche, and pocketbook.
You understand, however, that you're really just a middleman, serving the interests of the insurance company you work for above all else. Sure, you might sympathize with your customer's plight, but if you find that something isn't covered by the insurance policy, then there's not a thing you can do to help the claimant. Moreover, your duty to your employer obligates you to pay out the bare minimum on a claim, and no more, whenever possible. You wouldn't want to cut into your employer's profits now, would you?