Here is a current example of poor training:
I recently finished training a young guy to fly. As part of his training we stalled the aeroplane with power on, off, clean, landing configuration, turning and induced wing drops (I'm also a GA instructor and teach aerobatics, so am comfortable to train correct stall recognition and recovery within the limits of RAAus aircraft). Having gained his pilot certificate at an FTF a fair distance from his home town he decided to get checked out in a local FTF aircraft. During the upper air sequence he was to demonstrate a stall recovery, he tells me the instructor almost wet himself at the suggestion of stalling the aeroplane in a turn! The FTF insists on glide approaches, but don't allow slipping but use s-turns to lose height. When asked why glide approaches in a Rotax 912 powered aeroplane was considered necessary he was told the earlier "Ultralight" aircraft had two stroke engines which were prone to stopping, so every approach is a glide approach and have carried on this practice.
A couple of points here:
1. The operator insists on doing low level turns on final approach to lose height, yet doesn't teach or practice stall recovery in turns.
2. The operator's reasoning for glide approaches in a modern 4 stroke powered aeroplane is like teaching Cirrus SR22 pilots to do glide approaches because that's what was done in Tiger Moths.
I'm quite sure there are poor practices in GA too, but from my observations some instructors can't put training of certain sequences into context. I don't know what the answer is?