Thank you for this. I should have been clearer in my post -- with respect to "professional development", I meant primarily "dedicating time to finishing papers describing the students' work." Of course, publishing papers is directly in the interests of both supervisor and student.
The difference, though, is that the supervisor might publish four papers a year where he was the primary supervisor of the work, while the student might have a single first-author paper that he spent three years on. That paper is critical for the student to graduate and progress with his career, but for the supervisor, that one paper doesn't matter nearly as much, especially after hitting tenure. Both in my lab and others, I've seen projects stall for months or years because the supervisor is unwilling or unable to devote the time to revising a paper and preparing it for journal submission.
The difference, though, is that the supervisor might publish four papers a year where he was the primary supervisor of the work, while the student might have a single first-author paper that he spent three years on. That paper is critical for the student to graduate and progress with his career, but for the supervisor, that one paper doesn't matter nearly as much, especially after hitting tenure. Both in my lab and others, I've seen projects stall for months or years because the supervisor is unwilling or unable to devote the time to revising a paper and preparing it for journal submission.