Does the interviewer explain what bubble sort is, or do they expect the candidate to know it? The first is a reasonable interview, the second one isn't.
But, for the most part; I can't imagine anyone ever having to write it on the job unless they are doing super low level stuff. All the 'current' languages provide sorting algorithms built in.
It also kind of depends on the person. If you're interviewing an intern who's still in college, absolutely they should still remember bubble sort. If they don't know it off the top of their heads, they weren't paying attention in class. If you're interviewing someone who went to a boot camp then it would be expected that they wouldn't know a lot of the trivia like bubble sort that nobody really uses.
I assume that most people were taught most of the same material as I was, but in reality that may not be the case.
It's very hard to pin down what sorts of things "everyone" should be expected to know. I agree with the consensus that whiteboard coding and CS trivia is not a good way to run interviews, but I bet many/most of the people who complain the loudest about interviews have their own misconceptions about what constitutes common knowledge for programmers.
Any hiring process based on asking several current employees to take turns talking to someone for 30-60 minutes and make a hiring decision based on that is going to be deeply flawed. However, the only alternatives I've heard are so much more costly, lengthy, and elaborate that I just can't imagine many companies moving to a different process anytime soon.
This debate is also complicated because different people want very different things out of the process. Job seekers want processes that minimize false negatives (i.e., they don't want to fail the interview even though they'd make good employees), but employers want processes that minimize false positives (they don't want people who get through the hiring process that end up being bad employees that the company is now stuck with).
The current process probably doesn't do either of these things. But every more elaborate process I've heard people say they want seems to go to one extreme or the other- it either greatly favors the job seeker who hates false negatives, or greatly favors the employer who hates false positives. It's a hard problem with no good answers yet unfortunately. :(
It was covered in my first year CS courses... something like 9 years ago. I've not once needed to be able to re-implement it (or any sorting algorithm) in the intervening time finishing my degree and five years doing software dev as my day-job, much less re-implement it from memory. I would need to look it up to refresh myself on its implementation and characteristics.