This scientist treated her own cancer with viruses she grew in the lab

The problem is not that Halassy used self-experimentation as such, but that publishing her results could encourage others to reject conventional treatment and try something similar, says Sherkow. People with cancer can be particularly susceptible to trying unproven treatments.

I think they're going to try unproven treatments regardless, especially if there's a high barrier towards conventional treatment. The difference is whether they'll be swindled by quack cures or use something with demonstrable effects.