I also absolutely love GCs, particularly when the person puts effort into finding one for a store they know I like. For instance, one friend got me one from the local quilt shop that I didn’t even know had GCs. I also got some for the local big-box craft store (hooray, I’m set on notions and batting for a while). The cash I receive usually ends up being spent on practical things (like covering the boarding costs of our dog over the holidays, this year)
I do understand how they can go wrong though… one year my SO received an airline one from his Aunt, for an airline that doesn’t do flights at any of the relatively close airports to us—I think that was before the new regulations that restrict expiry dates, so it ended up expiring before we found a use for it or a way to trade it. This year was a gas card that would have been perfect for us—except that in 3000 mi of driving over the holidays, we never found one of those branded gas stations, nor are there any near our home. At least we can use it at Easter when we visit them, as there are locations near her house.
Ultimately, they are like any other gift: it can be obvious when there is thought put into it vs. when they just grabbed something that was easy. It’s just that the threshold for thoughtless is a little higher, because something like an Amazon one can be so widely appropriate (unless of course the recipient doesn’t like shopping online).