That's funny, I actually thought on first reading that it was a 4-legged baby they were expecting (donkey or horse) and they needed the stall and paddock space
Which seems entirely legitimate to me.
And I think you would have a hard time selling even a GOOD WELL-TRAINED jack on shortish notice in many parts of the country for more than like $600 - they are not exactly a hot commodity with a large market - so I would not make too many assumptions about Horrible Evil People Who Won't Remove Testicles Of Totally Un-Breeding-Worthy Male Animals. Just can't tell from the ad.
If it *were* because of an upcoming *human* baby, honestly I think that could be quite legitimate as well. I don't know whether you've had multiple equines and babies at the same time Shellie but I can tell you that it has been extremely difficult for me to get it to work, especially in wintertime. If I did not have the ability to keep ours on 24/7 turnout I am pretty certain I would have had to find new homes for them when kids came onto the radar, because there is just no way to go out and spend 45 minutes mucking stalls in -25 degree weather with no husband home and a young baby. There just isn't.
Even with dogs or cats, I think sometimes people DO legitimately have to give family matters priority -- when you adopt (or buy) a pet it is just not possible to be ABSOLUTELY sure that you will not suffer a major financial reverse, or have to move to a new location where there's noplace to live that will take your pets (in some cities it is exceedingly difficult to find apartments that are both habitable *and* inexpensive *and* allow animals), or have some sort of a family-circumstance change that is not compatible with animals. For instance some peoples kids ACTUALLY DO turn out to have very very severe asthma around the pets. Whatcha gonna do, sign the kid over to child protective services to be put in a foster home just so that the cat can stay?
I know these things are probably somewhat of a minority, among situations where people are giving up a pet, but THEY ARE REAL and I don't think they are quite as hens-teeth rare as people often like to pretend. I think it's important to preserve the line between getting aggravated at specific people for doing specific things, versus getting all hate-y at people in general who can't keep their animals.
Frankly I'd say the seller of the donkey is actually being pretty responsible in a) placing an ad (not taking him to auction or dumping him on a rescue), b) pricing him at low, and c) starting this in late summer when there is a greater chance of finding a taker.
JMO,
Pat