Becker's view is pretty straight forward: We cannot incorporate a true understanding of our inevitable death into our psyche and function, so basically a huge amount of the complexity of our psychology is based in ways our mind is able to divert accepting this reality. When I was younger I though "fear of death" was a wildly over blown notion (I remember reading Delillo's White Noise and thinking "is death that scary?"). But as I got older, and started having friends die, I realized that in youth I was just much more deeply in denial of death. Needless to say I think Becker makes a good point.
For me, the violent reaction by the psychology community against TMT seems to only add validity to Becker's idea. We really can't deal with the reality of our own personal death, and that is so strong that on an intellectual level we immediately was to laugh off the idea so that we don't have to face that this might even be the case.