Strong words, Phil.
The 150 became the aircraft it is, probably the most common trainer in the western world, not by being the best but by being the cheapest. You don't have to look far to find better performance, nicer handling or prettier aircraft in the same class.
Just off the top of my head, the Beagle Pup, Rollason Condor, Slingsby T-67, Jodel D150, Robin DR400-108. I'd choose any of them before flying the Cessna!
Then you may want to discuss the role of 'trainer'. A good trainer should really be an awful aeroplane (or be able to exhibit/exagerate various aerodynamic characteristics) so the student may develop the skill to be able to handle whatever aircraft he may later fly. The 150 is quite a pleasantly handling aircraft requiring less in the way of skill than other trainers of the era, typically the Auster.