Cycling lessons and other tips how to encourage beginners?

It's a real puzzle to me that Cycling Proficiency is still so well known but Bikeability is not.

As you say, 'Bikeability' is a poor choice of name. 'Cycle/Cycling Proficiency' has been around for a lot longer and is a set phrase. It was never a 'brand name', even though we might well call it that today. It sounds a lot better and for many people has pleasing associations with their youth, with their desire at the time to be mobile and to break out of their immediate surroundings, as well as with the underlying idea of making cycling more respectable through educating people in it.

CP never really achieved the last aim (cycling continued to decline) and was mired in a confusing and partly contradictory policy context which meant that it actually sent out a few mixed messages, some no doubt unintentional, others very intentional. For instance, unintentionally, that warm flashback to cycling as a young person (CP as a rite of passage, an exam to be passed) also embedded in people the idea that cycling is only for children (or poor people) as a means of transport, or only for leisure.

I don't know if CP was ever used for adult training, but certainly one of the main strengths of cycle training is that it encompasses adult training. 'Cycle training' isn't a great phrase, either, which you can see in how it's often received by people being recommended it, but no-one's found a better name yet.