Three issues with pusher-prop "tail-less" designs:
1) While they are more stable in nominal flight regimes, they are far harder to recover to stable flight from perturbations. It turns out, it's (overall) much safer to have a plane that will BOTH stall easier (more predictably) and recover easier than one that is less likely to stall in the first place, but difficult to recover from. One analogy I often use is the difference between a mid-engine car and a front-engine layout. While the mid-engine car has a greater overall theoretical "handling" performance ceiling, a front-engine car behaves more predictably (less twitchy) at the limits.
2) They are more susceptible to CG/balance issues so they have less practical cargo capacity because just a weee bit of pitch/yaw/roll trim results in a drastic drop-off in the aforementioned stellar lift efficiency.
3) They have much longer take-off and landing runway requirements due to less ground-effect and much less overall wing efficiency at near-stall speeds.
1) While they are more stable in nominal flight regimes, they are far harder to recover to stable flight from perturbations. It turns out, it's (overall) much safer to have a plane that will BOTH stall easier (more predictably) and recover easier than one that is less likely to stall in the first place, but difficult to recover from. One analogy I often use is the difference between a mid-engine car and a front-engine layout. While the mid-engine car has a greater overall theoretical "handling" performance ceiling, a front-engine car behaves more predictably (less twitchy) at the limits.
2) They are more susceptible to CG/balance issues so they have less practical cargo capacity because just a weee bit of pitch/yaw/roll trim results in a drastic drop-off in the aforementioned stellar lift efficiency.
3) They have much longer take-off and landing runway requirements due to less ground-effect and much less overall wing efficiency at near-stall speeds.