Saying to an individual mother that formula feeding will make her baby die is bad practice. Making it known that formula feeding puts a baby at risk for many diseases and even death is not hyperbole, but fact.
As for women who feel guilty about formula feeding... Why on earth would someone feel guilty about doing the very best thing she could in a particular situation? If BF or donated BM is simply not possible for a mom, for whatever reason (lack of education, lack of support, health issues, adoption, etc., etc., etc.), then FF is the right choice. Period. This mom should be proud of feeding her baby in the best way possible, not guilty.
This business about "making moms feel guilty" is crazy talk. Nobody can make another person feel guilty. Guilt is an internal response to a personal choice.
The only person who should feel guilty about not BF is the person who knows the facts about BF and has the ability (in all respects) to do it -- but chooses not to.