There is a lot of of tabular data in this world. If you aren't supposed to use tables to display it, then what should you use?
I don't know any CSS gurus (or their fawning acolytes) who think tabular data shouldn't be displayed in tables. The issue is non-tabular data being "boxed into place" by an invisible grid made from an HTML table. IOW, they intend the HTML table element to implement the concept of tabular data like you say, and not implement the concept of fixed placement in a grid; the two concepts are distinct. The only "purity" involved is wanting the second concept to have its own implementation, separate from the first.