They are weighing cost-to-benefit ratios & generalizing to come up with policy recommendations. There are always exceptions to rules. Back when I was 1st diagnosed in 1980, my gastro told me about
a 78 yr-old man who was too frail for major surgery, but who was doing well several months after she removed a malignant-core polyp from his ascending colon via c-scope. Doctors who care about
individual patients would likely ignore this age 75 recommendation! / Old Hat (nearly 30 yrs with left-sided UC ... [etc.])