Given that there is an enormous oversupply of philosophy Ph.D.s, don’t departments (esp. those with bad placement records) have a responsibility to admit fewer students to Ph.D. programs? or at least to take some reasonable means to prevent them from having terrible employment prospects once they’ve made it through 5 or 7 years of grad school?
Perhaps they could admit people to the philosophy Ph.D. only with a declared and reasonable “Plan B” career. Or they could force them to publish or perish by, say, year 4 of their program.
I think most philosophers believe that the answer to your first question is Yes, departments have a responsibility to admit fewer students to Ph.D. programs. This is especially true in the case of departments that are admitting students but not giving them funding. Most philosophers would say that that’s an irresponsible practice.
My sense is that most philosophers would also say Yes to your second question – departments should take reasonable steps to prevent their own students from having terrible employment prospects once they have completed their degrees. One good way to do this might be to provide resources for students to find work outside of academia. There is probably some pressure on departments not to do this, since it may be taken as a signal that the department is not serious enough academically, or is admitting that it cannot compete with higher-ranked departments for the top jobs. But surely that is a silly attitude – people need jobs, and it would be better for everyone in philosophy if getting a non-academic job was considered to be (and was!) a live and respectable option.
My own view is that a good way to get more departments to work seriously toward placing their students in non-academic jobs would be to create a central location that provided some relevant resources (for both job-seekers and prospective employers). For example, perhaps the APA could have a website devoted to this. That way, an individual department that provided links to those resources would look like (and would be) part of a solution to a common problem, rather than looking like a department that was admitting its own academic mediocrity.
Update, 7 Nov 2013: Coincidentally, there was an article published on November 1st in the NY Times about this general problem for Ph.D.s: http://www.nytimes.com/2013/11/03/education/edlife/finding-life-after-academia-and-not-feeling-bad-about-it.html?src=un&feedurl=http%3A%2F%2Fjson8.nytimes.com%2Fpages%2Feducation%2Findex.jsonp&_r=0&pagewanted=all.