How does anyone become an aid worker?

Have no experience whatsoever except living amongst indigenous communities around Asia in 2006 and 2008 for a short time, but all humanitarian agencies reject my application on these grounds. I find this extremely unfair as some of the best candidates do not have any field experience but can compensate this with a desire, heartfelt conviction and empathy to help the destitute and the lost rather than head knowledge and experience of academics who sometimes take projects as an intellectual exercise (not all). There are not enough people helping as it is and yet too many are denied that privilege to help because of a different kind of discrimination showing preferrence for PhD candidates or medics.