Criticism of Arroyo for trying to do something he either wasn't physically capable of or something that was unwise/unnecessary in the situation? Sure, I get that.
Criticism of using Arroyo at 1B at all? That's what's for the chunderheads. Swihart, for example, got hurt (over?)aggressively pursing a flyball into foul territory. It was a fluke occurrence. Ellsbury got trucked by Adrian Beltre. Again, a fluke occurrence. But that didn't stop the chunderheads from ripping Sox management for playing those guys "out of position" in LF and causing their fluke injuries.
While he hasn't gotten hurt doing so, I've seen Dalbec making similar poor decisions that a more experienced 1B would know not to make (like backing off a short throw and catching it on a high hop instead of stretching to pick it on the short hop). Just as he'll figure it out with experience, so can Arroyo though unfortunately Christian might be learning the hard way.