BlklynJen- I'm so sorry for your loss.

About stress and milk supply- stress can effect the milk ejection reflex. Severe emotional trauma CAN make it seem like "the milk goes away suddenly" when in reality the milk is still there but not coming out. Within a few days, milk supply will actually decrease if the breast isn't effectively emptied.
About the general topic:
I think we should treat all mothers with the respect we want to receive ourselves. We can disagree with a woman's choice without putting her down. Many women make "lame excuses" for not bf when in reality, they had valid, highly personal reasons they didn't want to share. Sexual abuse is one example. Lack of support in the face of difficulties is another.
I beleive that breastfeeding activists should address the underlying reasons that many women choose to formula feed without attacking mothers in the process.