Originally Posted by IO540
Why should a shallow final turn be more of a killer than a non-shallow final turn?
Because in a glider you have enough elevator authority to stall the glider in a shallow turn, but usually not (except perhaps in a few rare types) in a 45+ degree banked turn. Thus, even if suckered (by ground proximity, other aircraft, events on the runway etc.) into pulling back on the stick, you won't stall, drop a wing and spin in.
Also, a 45 degree turn uses less height overall (in gliders you will necessarily descend during the final turn unless there happens to be lift there) and is easier to judge so you end up pointing in the right direction, rather than displaced to one side of the runway or field.