We do indeed restrict ourselves to tabular structures of data, both on the web-page level and outside. Many non-technical people think in terms of spreadsheets

We do indeed restrict ourselves to tabular structures of data, both on the web-page level and outside. Many non-technical people think in terms of spreadsheets and tables. If you give people the spreadsheet/table as the data structure primitive through which you're iterating, they get the concept of a loop straight away. Couple that concept with teaching them a variable, and they can achieve a lot.