1. Police officers don't retire with "Massive lump sums and very high inflation proof pensions for life". Police officers pay a significant part of their salary into their pension fund and to get a lump sum let alone a "massive lump sum" they need to commute (give up part of their pension).
2. The figure of 10% sickness is a myth it's nothing like that. The term "sickness" covers a wide rage of issues from from flu, to a genuine illness long term chronic condition, to being injured as a result of assault on duty.
3. If you were getting the brick dust kicked out of you one Saturday night, would you want a 60 year old police officer turning up to help you? No! I didn't think you would.
We don't have 60 year old police officers for the same reason we don't have 60 year old soldiers. Front line policing in today's society is a young(er) person's job.