In what way can Bitcoin be considered a meaningful alternative (however you define it) if you also have to input a valid credit card number (that, presumably, the merchant will run the traditional $1 verification charge on)?

The reality is that Bitcoin is less convenient than using a regular credit card (because, realistically, you're not going to be mining Bitcoin but rather you'll be buying Bitcoin using your regular credit card/bank account). I would argue that Bitcoin is also worse in every way (no chargebacks, wild fluctuations in the valuation of a unit of Bitcoin, etc.) if you also don't care about anonymity and the product you're buying is fully legal.