The guys in the past trained for those fast finishes. Ryun ran 49.7 in a 3:38.2 race (sometimes claimed to be 50.6, but watch the tape). He ran the last 300 in 36.4 - and the race was electronically timed, not hand timed. These guys trained for speed. Scott ran a 52.5 last lap in a 3:49 mile. How many guys are doing that today - or seem capable? Maybe El Guerrouj at his peak.
But, different eras. The finish by the Spaniard was fast, but had me wondering how Ryun would have done with today's tracks, etc. That track he ran 3:33 on was shit, chewed up from two days worth of races. You can see how bad it was in pictures. He still finished in 39 on dirt, and people today get worked up over Webb running 4/10ths faster than Ryun over the 1500 - but coming through the 1200 over three seconds faster than Ryun did in his fastest race. And Webb had guys on his tail all the way to the finish. Webb is still a bit away from being as good as Scott or Ryun. He hasn't even run as fast as Krummy or Holman, never mind Scott for cryin' out loud.