Why is styling table columns not allowed?

Question

W3 specifies that only four CSS rules are allowed for table columns (with the element) - border, background, width and visibility.

Does anyo

Answer 1

Just a wild stab in the dark based upon my limited understanding:

I think styling via column related elements is restricted because although and represent columns of cells, it does not actually contain them (they're actually contained by the s). With this comes issues of precedence and specificity and cascading (since cascading can only be done between contained/ container elements) - when conflicting style rules from the and (which would be the same level in a multiple inheritance hierarchy) occur - which should the cell actually use?

As to why that particular handful of style attributes is permitted though: no idea.