It's not about the complexity of the aircraft, it's entirely about the
quality of the instruction.

We do about 4000-5000 instructional flights a year, mostly on ASK-21's,
about half of that is ab initio, and we like to think that our standard of
instruction is pretty good. Our experience is that however well you train
students, they sooner or later still need just that little extra room for
error while honing their skills, especially when flying early solos. An
ASK-21 will give that room. A Janus C is a lot less likely to do so. Then
there's also the maintenance point of view: Schempp-Hirth just does not
stand up to the punishment and wear Schleicher can take.

It's not a question of being able to use a Janus C for ab initio. Sure you
can. But does that mean I would want to? No. Not when there's so much
better available.

Just my two cents.