Yes, you don't (pretend to) remove the pillar without having something better in place to hold up the building.
The BC Citizens Assembly did provide that blueprint. This Calgary professor presumably knows that STV was used there for about 30 years in provincial elections and some 50 years in municipal elections. As ever, partisan considerations weighed in its removal. 
Richard Lung. "Democracy Science" with links to 3 free e-books on election method and science.