I was teaching mathematics to complete beginners, and finding that while they were fine with arithmetic, algebra completely eluded them. The moment one said “let x be the number of apples”, their eyes would glaze and one knew they were lost. But the same people had no problem entering a number into a spreadsheet cell labelled “Number of apples”, happily changing it at will and observing the ensuing results
This is one secret of the mass accessibility of spreadsheets: they don't require abstraction—you build a concrete working example, then tweak it. This differs from other programming environments—even the simplest scripting languages—which require you to build abstractions first and only later instantiate them. That is a high cognitive hurdle.