Dear Szabolcs,
I actually use both RPi and IGraph/M. I often do live coding with pupils as well and sometimes IGraph functionality is a very-nice-to-have. Often neither schools nor pupils have the money for a proper computer. This is a very nice way for them to get into programming. (And yes this is not an "in principle" thing; in fact next Monday a colleague of mine and I will spend the entire day at a school teaching computational thinking to pupils and teachers, and I will be using IGraph functionality.)
I understand that neither me nor these activities would justify your work on this, but your work is very useful and I think it makes a difference in these cases.
Best wishes from Scotland,
Marco