A GA aircraft is not an airliner. Bugging speed in an airliner works because of OTHER flight regimens. For example, no airliner is going to pull a lot of G nor is it going to roll past 30 degrees, because of SOPs predicated on passenger comfort. Consider the inexperienced pilot in his PA-28, manoevering to land at an unfamiliar airport. He hasn’t considered the tail-wind on base leg and he overshoots the turn to final. He rolls into a steep bank and pulls G to recover the centerline. He’s going to die regardless of a line painted on his airspeed indicator. We need AoA indicators in aircraft, not airline speed-bugs.