Because he thinks putting Sanchez in the pen last year was some sort of stroke of genius, I guess. I don't necessarily think there's a "good" reason but I don't believe for one second that West and Guilmet were given the same opportunity as Castro and Osuna. There's just no evidence of that. That's AA for you. He's only half-smart. Like he does some stuff that makes sense but he also does some dumb stuff like over-paying for middle relievers in trade (Lincoln, Rogers, Francisco) or bad rosters assignments (Sierra, Thames). AA's not the kind of guy you can just give a blanket benefit of the doubt too. You just have to take the good with the bad. This shoudn't hurt the team in the short term. These guys will be fun to watch but West and Guilmet would have probably been fun to watch too and with no long term cost. It's not a decision you can rationalize. The simplest explanation is often the correct one and the simple explanation here is that this was just AA's dumb prerogative. People in positions of power don't always do what's best for their organization. They go with their gut and do dumb stuff. You probably see stuff like this all the time in your own work environment. The people making the decisions aren't necessarily the smartet peoples, they're not necessarily the dumbest. They're just the people making the decisions.