Mr. Alacrán is El Patrón's great-grandson and the heir to Opium. This might seem like a sweet gig, but you wouldn't guess it from Mr. Alacrán's attitude. The guy is perpetually in a grouchy mood. When we examine his life a little more closely, we get some clues as to why he's so miserable.
First, he's trapped. He's stuck with El Patrón, and he's poised to inherit a seriously screwed-up country, if the old guy ever does finally croak. But because El Patrón plans to live forever, Mr. Alacrán has probably resigned to living out his life as a prisoner in Opium. To top things off, Mr. Alacrán's kids are punks and he is stuck with his cheating, depressed, alcoholic wife because El Patrón won't let them get divorced. It's no picnic, that's for sure. No wonder he's in a rotten mood.
It might seem like his lot in life might be enough for us to cut Mr. Alacrán some slack. Not so. The main reason we're not big fans is that no matter what, he always chooses to keep up things as they are. He adopts El Patrón's prejudice, because he can't think for himself. To be fair, we have to grant the possibility that his mean attitude towards Matt is partly a way to spite El Patrón, who pays more attention to Matt. But Mr. Alacrán is also just downright prejudiced towards eejits and all the other clones. His decision to have Matt killed after El Patrón's death reveals what a hard man he has become. And that's why, in Shmoop's book, he's pretty unredeemable.