An adjuster applies a policy to a set of facts. Most claim disputes come down to whose description of those facts was written down first and in more detail.
A complaint lands in a queue in front of somebody with a script and limited authority. Knowing what that person can and cannot do changes how you write it.
Exclusions read like a list of ways to be turned down. Most of them exist because the risk they name behaves in a way ordinary insurance cannot absorb.
All three feel like costs of earning a living, because they are, and all three are generally not deductible. One piece of reasoning explains every one of them.