Not sure they devalue defense that much, rather, you have to accept that every player comes with a set of tradeoffs.
Until Crawford is healthy and acclimated to ML play, there is no plus SS option, Franco's upside is average, Williams is average, Hoskin is average, but all three are works in progress.
Altherr and Quinn could give you plus OF defense, but right now they can't hit enough to make that valuable.
Kingery is a minus SS who is improving but a plus 2B.
Cabrera is a minus SS, average 3B, below average 2B, at SS and 3B he's not going to be significantly different than what they already have (and Machado is probably as bad at SS)..
Galvis wasn't traded because they didn't value defense (they were considering bringing him back) but because they had to make room for Crawford, and Galvis didn't have the skill set of a bench player.
Kilome wasn't a big price to pay, I soured on him last year, he's flatlined and looks like another guy with velocity but no command who bounce around, and I'm not sure he fits the RP mold. He has time to turn it around at 23, but not sure there was room. De Los Santos, Romero, Medina, S Sanchez are ahead of him, and Suarez might be as well. And they have a lot of solid A ball SPs who may have pushed him next season.