Hmm, I remember wondering how you can have a venturi effect with only half a nozzle and never really believed that theory explained it...Newton's third law does it for me. Pretty easy to demonstrate, otherwise aeroplanes wouldn't be able to move forwards and get airspeed in the first place!
Had a student once who had done a project at uni where they had to make a stop sign creat lift, and they succeeded. No venturi effect around a stop sign!
It does bug me when the theory is dumbed down, but hey as long as you can predict lift I guess it isn't vital to be as nerdy as me.