Whatever long term choices mothers make - at birth babies need colostrum and there is no alternative, no synthetic substitute and i can see no valid reason why any mother would plan to deny their newborn of this.
There is something very flawed in our society that has resulted in a culture where its acceptable to not provide your baby with milk that has been designed for them, simply because the mother didn't like the idea of it or found it tough.
In other countries there isn't this 'either or' - the presumption is always that breastmilk will be offered.
Of course if there is a medical emergency that child needs to be feed, but in those circumstances where the baby needs to be separated all hospitals have provision of formula.
As for people saying it made them feel suicidal, there is actually a strong link between ff and postnatal depression, not the other way round. Breastfeed has huge psychological benefits to mother and baby, both in the long and short term. If establishing breastfeeding was making a mother suicidal I would suggest there is an underlying issue or struggle there that needs to be addressed, not simply reaching for cow and gate as a solution.
Some things are tough after childbirth - I had a 4th degree episotomy and terrible piles for months, and going for a poo was really hard and got me really down, i even cried at points and it was painful and stressful!
But I didnt decide to quit pooing - or seek out an alternative, I got on with it and ate a lot of fibre.
Breastfeeding is as natural, normal and essential as going for a poo!