Its worse than that.
While those working at private companies can at least earn a little money, they face possible punishment if they refuse, from being denied family visits to being sent to higher-security prisons, which are so dangerous that the federal government filed a lawsuit four years ago that remains pending, calling the treatment of prisoners unconstitutional.
Feral horses are a problem in the American plains and west with one of the issues being the fact their carcasses will attract grizzlies or black bears which can then encroach on humans. Hiking out, digging a massive pit, and then burying a horse really isn't an option so they blow them up to increase the speed of decomposition.
They also degrade and destroy native grassland and the whole problem could be easily solved with a cull of the herds, but some dipshit-wanabe-cowboys are obsessed with "saving" "wild" horses so now the federal government has to spend over a $100 million on horse contraception to keep the population vaguely in check.
TDLR: We blow up a bunch of horses corpses every year because of a politically connected nonprofit.