It wouldn't have happened in an A320 with competent pilots either. Or an Embraer or a Bombardier or a Piper.
No doubt the accident crew was competent, but unfortunately not for what they what they got themselves into. As with the "competent" Cali crew in P51guy's post, they made a huge mistake that day. It might be borne out by the CVR and FDR that through most of the flight, they did things well. Save for one. And that one thing was the one that killed them.