Why is this? Your father or grandfather probably expected Bannister to physically explode or his heart to give up while attempting to run the 'clearly impossible' sub 4 minute mile.
It's been over a quarter of a century since Komen's WR. A quarter of a century before he ran it, the WR was 7:39. Komen took 4 1/2 seconds off EPO juiced Morcelli's WR set just 2 years before. He ran 9 seconds faster than Aouita's WR set just 7 years previously, and which was likely the last non EPO WR, although Aouita was almost certainly blood doped and roided to the max.
Of course Komen would have ran a lot faster in super shoes and modern tracks. It's plausible he could have ran 7:12, and it's plausible El G would have ran close to 3:20 for the 1500m. That doesn't show how stupid super shoes logic is, it shows how insane the full throttle EPO era was.
More sensible is to look at guys like Coe and Cram. They ran 3:29 for 1500 and likely would have ran 3:25 today. Jakob could very well run 3:26 this year and was certainly in 3:27 form last year. So that seems about right - that Coe and Cram were about a second or two quicker than the best today are (currently).
Or look at it one other way. If there had been no testing for EPO worldwide for 10 years, zero random testing in East Africa for the last 10 years, and Gentleman Tim had been epo maxxing since he was a teen, with hgh and roids too, what might he have run at Monaco in the last 3 or 4 years? Probably something like 3:22