Gladwell is a good runner. You can cut him some slack on the article. Look at his main points. He's trying to show that since the barrier was broken we've come a long way in being able to go sub 4. High schoolers do it now; back then they surely thought you needed to be fairly dedicated and a few years older. Now the younger kids are training more than those older kids did. Not only have we lowered the age, but it doesn't have to be a do-or-die one mile race to do it. Remember when Pre said he was going to run the last mile of his 5k in 4 minutes to win the Olympics? It can be done as part of a longer race even if Gladwell does exaggerate how easy or common it is. If you want to disagree with Gladwell on the basis that it's not all that common, okay. But I think Gladwell's point might be that Bannister pushed us through the barrier and made people believe they could do it, so the commonality is a compliment in a way.