Haloperidol has one of the highest rates of side-effects[1], like permanent movement disorders, in its class, and it is neurotoxic[2]. Movement disorders like tardive dyskinesia don't seem like a good time.
Second generation antipsychotics typically have lower affinities for dopamine receptors compared to older drugs, thus lowering the severity of side-effects associated with dopamine blockade. They have much lower risks of causing movement disorders. They also bind to dopamine receptors differently than the strongly antagonist first generation antipsychotics. Some of them are partial agonists, inverse agonists, and full agonists with lower affinities at dopamine receptors, so they have less "anti-dopamine" activity than haloperidol and older antipsychotics do.
I agree with you that these drugs have terrible side-effects, but I'd argue that being loaded with haloperidol is one of the worse options to be treated with when it comes to bad side-effects. There's immediate release inectable versions of olanzapine, ziprasidone and clozapine, all second generation antipsychotics, but I suspect they cost more than haloperidol.