I think people are misremembering Taylor's injury problems a bit.
The ankle against Missouri continued to nag him the rest of his career as far as never quite getting back to that level of acceleration and burst, but his sophomore year he was hobbled by turf toe (which led to the hilariously mocked throwing motion examples), and then his junior year was supposedly "healthy" as far as we know. Then he had, I guess it was never publicly disclosed exactly, a broken foot or something from kicking the locker his senior season that they tried to hide and also publicly diagnose as turf toe.
That ankle injury took him down from the "we've never seen anything like this before" level of athlete he was, but that foot injury his senior year was pretty tragic - he was putting up amazing, efficient numbers through 3 games, improving upon his already highly improved junior season. It's too bad.