If he is a baby or a juvie, that is defensive behavior. He is afraid, and young beardies are still in fight or flight survival mode.
Don't approach him from above and grab him, that is what predators do. Put your hand in at the opposite side he is and slowlyyyyyyy move it across the bottom of the viv to him. Pick him up slowly and gently, and be sure to support all of his feet to make him feel secure. Don't hold him for extended periods of time, start with a minute or two and very slowly increase the amount of time you hold him.
As mentioned before, all beardies have different personalities. My first beardie, Rex, only liked me and my husband. He would try to climb down my shirt if anyone else came near him. He also never liked being out of his viv for extended periods of time, and didn't really like to cuddle. My new juvie's personality is more like Rex, but my 5 year old rescue loves to be out of his viv and loves to cuddle. I'm still working with the juvie, maybe he'll change a little. But I love him either way.