Spreadsheets can be reproduced and altered just as any code. I think the purpose of writing a post in code is mainly about keeping the code in sync with the exposition. But this was the purpose of MS Office before R even existed.

I am skeptical of spreadsheets, but is there any evidence that they are worse than any other kind of code? Indeed

These error rates, although troubling, are in line with those in programming and other human cognitive domains.

(I am not sure what that means. If the per-cell error rate is the same as the per-line rate of conventional programming, that definitely counts as spreadsheets being terrible. But I think the claim is 0.5% per-cell error rate and 5% per-line error rate.)

Even if there were evidence that spreadsheets are worse than other codebases, I would be hesitant to blame the spreadsheets, rather than the operators. It is true that there are many classes of errors that they make possible, but they also have the positive effect of encouraging the user to look at intermediate steps in the calculation. I suspect that the biggest problem with spreadsheets is that they are used by amateurs. People see them as safe and easy, while they see conventional code as difficult and dangerous.