Let's not get pedantic! Sales of limited-stock goods will ideally run their course in a super short span of time. For example if I am running a Magento site and am anticipating 100k+ visitors per minute, then I have to start worrying about the need for load balancers, etc. Shopify removes this burden. I think it's clear that that's what they're saying.
Harvard's CS50 begins with C and it's quite successful. Well, technically they begin with Scratch, but the course quickly moves into C. They get around certain barriers (you mention user input) by providing helpers/abstractions, which are gradually torn down as the course progresses.