Some people get into bad habits so that "natural" for them is not the best way to do it. Some kids will naturally try to breath attack everything because cause they were never taught they needed to use the tongue to play (this happened in my middle school because the director didn't teach or emphasize tonguing). I, like oldlou, never had a problem with articulation. I learned that tonguing concept fairly early by listening to soundtracks and it was pretty clear to me what I needed to do.
And good articulation is not natural, it has to be learned (I had to be taught legato and double tonguing) just like learning to speak. You can only learn so much by nature and by listening. In fact, nothing about playing the trumpet is natural UNTIL you make it a habit. But natural is not always right, or best.