Why Radio Buttons and Checkboxes Can’t Co-Exist

I disagree. It is clearer to use separate shapes (or different colours, or something to indicate the difference) for each case, I think, rather than merely the words used.

I can't say as I agree with pretty much anything this essay posits. But I do find it a bit ironic that many of the sins the author paints onto these controls are the same sins that have become very, very common in modern UI design.