I know exactly what you mean. I collaborate with another faculty member in my department, who allows me to help with her protects (not much going on in my own lab, so I try to get better training and experience). A year ago she had a student who didn’t even seem to understand what a graduate program was. Would ask really moronic questions about what a thesis was, and didn’t seem to get it. On top of that, she couldn’t do her own work. She submitted a first author poster, but I was the one who basically wrote her abstract and did the entire poster. She couldn’t even write an abstract or come up with an idea with the data in the lab to save her life. To give you perspective, she didn’t even know how to figure out the number of participants in a dataset. Everyone in the lab was fed up with her, and she would just annoy students in other classes with her dumb questions/comments and anecdotal stories that didn’t really contribute any substance to the discussion. Worst of all, a faculty member got in trouble for trying to report her for plagiarism, which she was definitely committed. Her advisor had to make multiple appeals to get her kicked out of the lab, but instead of kicking her out of the program, she was just sent to another lab. Now she doesn’t do anything but work on her milestones. Must be nice to be given so many chances for being incompetent and dishonest.