Don't worry too much about him hiding all the time- some snakes do, and in the wild its a very good survival strategy.
My Abby is a hider, and still spends most of her days curled up in her coconut shell or in her greenery with just her head poking out to see whats going on. As she became relaxed and comfortable, she began taking dusk and dawn prowls around her enclosure, but she still spends 98% of her time with all but her head under cover.

When I take her out its a different story- she is calm, gentle (Never struck at anything but food.) and is perfectly content to curl up in or under a hand or along the crook of an arm. She explores a bit, but seldom bolts unless startled- she just likes to feel covered and safe unless she is out hunting.

I think she now looks forward to handling as I feed her when the handling session is over. When returned to her tank, if she is even slightly hungry, she will climb into her feeding plant and wait eagerly for the food to appear.
Conditioning really does work!