That doesn't mean the columns did not have a purpose. Columns can create points that organize spatial experience. Columns are cultural iconography (e.g. the Parthenon vs Johnson Wax).
There are certain ironies in the fine article:
1. The criticism of the non-structural columns for non-functionality in the context of an art museum.
2. If Venturi and Scott Brown had designed a duck (very common among museum commissions) removing the columns would have been difficult or impossible [1].
For context, Charles Windsor's architectural opinions are contrary not just to the ideas of Venturi and Scott Brown but to the aesthetics of the last 150 years.
[0]: https://99percentinvisible.org/article/lessons-sin-city-arch...
[1]: Architects with functional dogma will incorporate structural columns into their designs to achieve iconography and spatial organization because structural use justifies their inclusion.