Why is failing to implement BFS/DFS/quicksort in a 45 minute interview the fault of the interviewing process being broken? The idea that someone has to study 3

Why is failing to implement BFS/DFS/quicksort in a 45 minute interview the fault of the interviewing process being broken? The idea that someone has to study 3 months for an interview is ridiculous. I suppose for a PhD student I can understand as they probably need to refresh their memory, but if that's the case then you could argue they shouldn't be passing the interviews without refreshing their memory if we are talking about normal software development roles.