So how much will the extra 3.5% benefit you? At what cost (time, effort, frustration, forgoing benefits of shopping directly with CC rather than GC, leftovers, etc. etc.)?
Is it penny smart and pound foolish?
Let's be blunt: unless one has a good MS and/or SUB strategy אין הצר שווה בנזק המלך.
I would agree with you only to a point. Everybody is different and everybody has different reasons for wanting points. For me, I have a daughter that will be going to seminary next year IYH and I would like to be able to visit her without the stress of needing to pay for it. So collecting points that I don't necessarily need to use right away is fine by me, because I know I will need them soon. But if I need to do Amazon returns anyways, I can time it so I'm going to Staples when they're having their promotions and getting more bang for my buck with buying gift cards.
With carrying only two or three cards in your wallet, you can really maximize things knowing which card to use in which scenario. I'm planning on buying tickets for Disney, and if I can save 5% just by buying Disney gift cards from Target, that is easy money in my pocket just by being smart about which card I'm using to buy the tickets with. (I recognize the irony of buying Disneyland tickets in this thread)