It doesn't make sense to model everything in terms of lists, but using 'cons' to make your own data structures doesn't force you to. A-lists and p-lists are bot

It doesn't make sense to model everything in terms of lists, but using 'cons' to make your own data structures doesn't force you to. A-lists and p-lists are both mappings that happen to use 'cons'. Are they efficient for thousands of entries? Absolutely not, but they work fine for a dozen, and you can certainly implement more efficient data structures on top of them. It's certainly true that modern Lisps have more structured approaches and this is a very cool improvement on those offerings. I just think "Scheme's approach to data is broken" is a little over the top.