I agree 100% with the above. C and P have done untold damage to GA with their product line.
However we get the leftovers from the American market, and Americans are very conservative, and American aircraft owners are extremely conservative.
If the main market for Cessna and Piper was in Europe, they would have gone the way of Norton, BSA, Enfield, etc, and at about the same time.
Undoubtedly a big factor is the tight regulation in the operating arena, forcing constant costly maintenance which in turn keeps old machines going, thus preserving their secondhand value. However it was easy enough for any enthusiast to keep his BSA on the road (in the good ole' days when you could buy a MOT certificate for a tenner
) and keep the oil constantly topped up - yet the market for these old machines dried up pretty quickly once the competition appeared.