I shop there frequently, and it is rare that I have a problem anymore. Many stores, however, exclude gift card purchases. Makes no sense to me.
"We will take your money that you may or may not spend in our store, but we aren't going to pay you miles for it. If we have to actually ship you a
product, however, we'll give you the miles."
The only logic I can figure is that there are some stores which do give miles for card purchases, and while I won't name any names, spending those cards through AAdvantage Shopping earns miles once again.
As a business owner, I would see that as the customer sometimes getting the better end of the deal. That's good for customer relations, and there would still be enough who would never spend their cards to make up for it. Assuming they price their products profitably, that is.