While I agree that some of the blame falls on the PIs, it should fall on the university system as well. My PI recently read his mid-tenure review to our group, noting that there are explicit publishing metrics evaluated by the department which play a major role in his performance review. Things like ranking of journals published in (ref. Reuters InCites), # citations etc. I understand a department's desire for a quantitative evaluation metric, but at the same time as long as this mechanism is in place the system will not change.