Earlier quoted context omitted.
I mean, it's all cultural. But the idea is that a gift is personal , and that cash is impersonal . The universality is exactly what makes it impersonal. The ideal gift (again, in US cultural context) is one that reflects something unique about the giver, or recipient, or the relationship between them. An exchange of cash is something that happens between strangers on a regular basis.
Lets be clear, a gift card is just as shitty a gift - it just manages to be a mite less crass
I do not want to carry a stupid gift card around with me, or have to remember to use it, or how much more is left on it. And the principle of it is that the cash they could have given you is now earning the retailer interest?