Well, obviously an edge is required if you want to trade profitably (you can always gamble and make money, but it's a legitimate edge that seperates one from another)... but I wouldn't go as far as to say traders are "born" instead of "made".
I mean, I suppose, if we all lived forever and had infinite sums of money, anyone could stick at it long enough. It is just a skill, after all. BUT, it takes alot of effort to get beyond the event horizon, as it were. What ultimately matters is how much you have to learn a) about yourself and b) about the market, and whether you have the 1) Time, and 2) the money to accomplish this. And I am assuming that everyone manages to get on the right path in the first place... you could spend alot of time and money switching from EA to EA and still have gotten nowhere.
That's why some people get it in a matter of months, while others just will never have the resources to overcome their own personal hurdles.