[erfgh]

The killer argument at the time (and even now most likely) is that screen readers could not distinguish whether the table was used for layout or for data and therefore sight-impaired users would have trouble.

The argument doesn't make sense because it is not too hard for a screenreader to understand whether a table is used for layout and even if it was hard the problem would more easily be solved by just adding an attribute to the table to indicate that it is used for layout.