It's not crazy. Often they'll try to "rescue" a few pigs to assuage their guilt about breeding 100+ pigs a year. Some of them utilize these "rescues" as additional breeding stock.
There may be responsible guinea pig breeders out there, but so far I haven't met one breeding for health and keeping their pigs in good conditions. (Many of them utilize tupperware totes and keep pigs in less than half the recommended space). No one can make the choice for you, but I don't understand why someone would support a person contributing to the overpopulation problem when their area has a ton of homeless pigs, many available through rescues who vet screen them and will assist you through every step of the pig's life until their death.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry