I really really don't understand why people get so offended regarding whiteboard coding interviews. I understand not liking them, and even disagreeing with them

I really really don't understand why people get so offended regarding whiteboard coding interviews. I understand not liking them, and even disagreeing with them, but walking out of a job interview because they ask you to solve a little puzzle doesn't make sense to me. When you apply for a retail job, they'll ask you a question such as "how would you handle X situation," and you're expected to come up with a plan on the spot. In reality, you'll probably have a manager who will tell you what to do, or you'll at least have a team to discuss it with, but asking questions like this tells you something about a candidate. The same thing with writing whiteboard code- it tells you something about the candidate. At the bottom line, it tells you whether the candidate can reason and think about code. It also demonstrates how the candidate can communicate their thoughts and questions with others on their team. Honestly I'd rather these skills be tested while I'm writing code, rather them asking some questions like "tell us about a bug you encountered and how you fixed it." I guess it also shows if the candidate has an ego too big to be willing to be interviewed for an hour.