Why can’t I consistently make money trading?

I suspect this question is commonly asked by most traders out there.
The simple fact of the matter is that over 90% of all traders lose money. The amateur forex day trader will most likely blow out their account within a few short weeks to months. Most brokers will tell you the reason why most amateurs blow out their accounts is that they are insufficiently capitalized. While that is probably true, it is clearly not the only reason.
I believe the primary reason most traders fail is because they are using a subjective and incomplete trading system.