That's nice in theory. But it doesn't fit the facts.
1) The whiteboard questions are unrelated to the job opening.
The interviewers have no idea why you are there. They don't know what your resume says. They don't know who you might be working for. They don't know what you might be working on. Would you hire someone to work for you without knowing if they were going to clean your house, install new lighting, or rebuild your kitchen? How exactly would you interview a person if you don't know why you need their skills? Or how their skills are related to the task? Asking a carpenter to "whiteboard" the steps to clean a bathtub during an interview is insulting.
2) The interview is being conducted by people who have almost no job experience.
My experience is that the interviewers are recent college graduates. And that the whiteboard questions are related to their data structures class. They are focused on details like worst-case behavior of the algorithm and whether you can quote the log-log-n asymtotic performance. This entirely ignores the fact that the actual behavior depends a lot on the actual measured performance. Take, for example, my paper on garbage collection (http://daly.axiom-developer.org/TimothyDaly_files/Bozm84.pdf) where the actual data access pattern matters. Theoretically strong algorithms usually exhibit bad behavior because of data access patterns, CPU caches, look-aside buffering, and/or branch prediction failures.
3) There is no known relation between being effective and being able to present information.
I know people who are strongly autistic, to the point of not making actual eye contact or giving any verbal feedback at all, appearing to be "not paying attention"... and then create beautifully crafted excellent code. I also know people who "talk a good game" and couldn't write a "hello world" page in html. Please point me to any study that shows that whiteboarding is an effective way to judge candidates. Even Google's HR head claims it is ineffective.
4) There is a ball-pit / clown nose aspect to the interview.
"Everybody does it" so wear the clown nose. I've had a fair number of interviews in my 48 year career. Most of them were with people who needed something done and I could demonstrate my ability to do that. Interviews exist for a reason. Asking me to whiteboard Knuth-Bendix because you're writing an editor is reasonable. But the same question for a customer service job would be nonsense.
These "clown-nose" interviews are simply insulting and a waste of time. Walk away.