I think that's what it is all about.
Unfortunately, deciding who is more likely to contribute between Brice, Mazza, Stock, Walden, etc. is a complete guessing game.
With Aybar, he is a bit younger and has the option of staying in the minors, so you have a few seasons to see if he can contribute.
If they DFA Aybar, it is because they just don;t think he has the talent. Sometimes that just doesn't work out either. While the Sox were trotting out this collection of retreads and hoping someone showed something, their own DFA in Jordan Weems was contributing in the bullpen of the AL West champions...