Retire Already! Are 70+ year old professors a drag?

Via Arts and Letters Daily and The Chronicle of Higher Education:
Professors approaching 70 who are still enamored with hanging out with students and colleagues, or even fretting about money, have an ethical obligation to step back and think seriously about quitting.
Click the link to see more: Retire Already! - The Chronicle Review - The Chronicle of Higher Education
Points:
  • “…three-quarters of professors between 49 and 67 say they will either delay retirement past age 65 or—gasp!—never retire at all.”
  • “…faculty who delay retirement harm students, who in most cases would benefit from being taught by someone younger than 70, even younger than 65.”
  • “Septuagenarian faculty members also cost colleges more than younger faculty—in the form of higher salaries, higher health-care costs, and higher employer-matched retirement contributions.”
  • “…their presence stifles change.”
  • “By delaying retirement, older faculty members, in effect, tell the younger generation of wannabe professors to table their aspirations to teach full time, or maybe even to give them up entirely.”
  • “…older faculty, by hogging an unfair share of the budget devoted to faculty salaries, exemplify the tragedy playing out in the larger social and economic arenas of all industrialized nations, where older members of a society, compared with younger groups, now possess a disproportionate share of a country’s wealth.”

Horns of a dilemma for which there should be a better resolution than to run these people off.