I sympathise with their frustration and have whinged a lot myself recently. However, getting some perspective on what other airlines are doing, the reality seems to be emerging that QF tickets holders are actually quite lucky compared to many. Not saying QF deserves kudos for honouring their contracts but even that can't be assumed anymore from many.
More importantly, however, and with respect, if Qantas cancelled her ticket and the writer nor his daughter pressed "cancel / voucher" in the booking, then she is still entitled to and will receive a refund. This can either be done in the voucher itself or by calling in. The latter may be annoying, but it will be time well spent for the refund.
Obviously Qantas is not communicating clearly and we know why, though it is backfiring as seen here. However, ultimately, Qantas isn't (yet?) denying anyone a cash refund for flights they've cancelled and bookings they've "unilaterally" converted into a voucher.
Surely if this fellow is willing to take the time to write into the paper, he will take the time to call into Qantas and realise the refund is being permitted after all.