Why are bitcoin gift cards not a thing?

I think someone like circle should easily be able to team up with a big merchant to sell something that is redeemable for bitcoins. The price could be fixed at either the time of purchase or at the time of redemption.

Give cash -> Get receipt -> Go home -> Redeem bitcoins with code on the receipt

Or better yet, the receipt could be a paper wallet itself, and be swept by any app you want. Although the incentives are probably stronger for a company that wants to get people to sign up for their wallet.