By this reasoning every transaction involves credit, since there's a time period between me swiping my card for the apples, and me walking out of the store with the apples, during which time you could tackle me and take my apples. And if it's a word that applies to every transaction, then it's meaningless.
Every transaction _does_ involve credit risk (specifically counter party or settlement risk) but the amount of it changes based on the difference in time between when payment happens and the transaction is completed. So for most purposes a cash transaction where I give you cash and you give me the goods is viewed as riskless (even though it's not as you point out).
But in your example, you don't need to invoke a security guard stealing your apples. There is a _ton_ of credit risk already just by the invocation of the electronic payment. Your funds will not hit the account of the merchant in question for _a long time_ (usually modeled as 1-3 days for risk purposes in the US). All kinds of things can happen in that time. The merchant has extended you credit and has taken on credit risk. They've done so because of the chain of credit and agreements that the banks, processors and networks have worked out.
If Mastercard gets a bunch of its transactions reversed because a Congressional panel gets huffy about pornography, that potentially blows up transactions for apples miles away. That's why this is mostly a conversation about risk management, not morals. To the apple vendor's bank, they largely don't care if you buy porn, they just don't want their settlements caught up in the blowback.
