Gifted can mean many things. You can have a guy mostly fast twitch who adapts to sprint training brilliantly and gets absolutely nowhere with endurance=biomechanics. A guy who has a high capacity to handle milage but has terrible aerobic response, adversely somebody with a super high/trainable vo2 who gets injured off 30+ mile weeks and would probably benefit from changing sport. There are even people out there who have terrible everything and hardly adapt at all.
As much as we would all like to think the most hard work gets the most results, the truth is this is not a fair sport. There will always be people worse than me, and people better than me. As a guy who runs a 19:30-20:30 5k I'd like to think of myself as average in terms of genetics. I know dudes who thrive off training and atrted out as 19 guys and ended up 15/16 minute guys within a year or two, adversely I know guys who train consistently with milage and speed work and are around 22 minute guys.
The truth is, I know this is letsrun where any guy who can't run under 18 minutes "isn't trying" but I really do know some slow ass folks who work their butts off harder than you'd think for their 20+ minute 5ks.