> It's very strange that the authors talk about how "making a bad hire is terribly expensive" but then call out "travel time and costs". Well, if B < A for each role filled, is it really so bad?

The cost of a bad hire they're referring to includes things like opportunity cost of not having a good hire in that position, damage they've done to the product (codebase, design, etc.), and second-order effects like demoralizing the rest of the team.

The actual hiring costs of a bad hire are a rounding error compared to the damage they can do.

Have you ever been on a team that was great until they hired one wrong person who made every work week a miserable slog? Attrition goes up as the good employees start to leave. The codebase starts accumulating a lot of tech debt. Even after they're gone it can take a long time to recover.

This is why it's so important to be able to fire fast, but that's another topic rife with difficulties.