Disclaimer - I know Cefn (and have met Grumpy Mike ).
I'm a primary school technican/HLTA and therefore the concept of learning a simple system before moving onto a "real world" system is the way it is with young children.
I learnt electronics from brick-type kits which I then threw away and built Heathkit type kits and I then I built a Linear Amp from scratch and then I went and had a career as a Transmitter Engineer.
So learning a "mickey-mouse" language is a great benefit at the beginning as it buffers the learner from the "real-world" and allows them to make progress.
I see the concept of first learning about programming an arduino via a higher level language on a PC before switching to its c-like structure as just part of the whole Lego/Mecanno learning concept 
regards
Simon