Each QCX kit contains SIX BS170 MOSfets...
That's 60,000 TO-92 MOSfets. So very many through-hole single-transistor
devices are now un-obtanium. consider that Hans may have single-handedly
kept these devices in production.
Some marketing person, somewhere might be scratching his/her head, and
wondering, "why is there so much demand for these ancient devices?"
Were it not for the QCX, we might find only SOT-23 type mmbf170.