WDC put out the call for Expressions of Interest late last year and had no suitable responses.
Harcourts' Peter Peeters described the city as "staggering and stuck". "Private enterprise is just shaking their head," he said.
Ms Mai said the CBD was "an embarrassment".
"It's dirty. It's got empty buildings. It's got businesses closing."
But, she said people were indeed partnering with the council and pointed to the business people who were using the new Cameron St laneway to put on free concerts on Friday nights.
"We can do the blank canvas but it's up to our community to paint the colour and add to the experience ...
"We've still got some tough calls to make but we are investing in the right areas. We will get that heart beating in the CBD, but by crikey, there are some people in the community that need to pull their socks up."
The meeting also considered more than 1000 pieces of public feedback WDC had received on its 20/20 Momentum vision document, as well as two community-led art and education projects.
Off the back of the zero expressions of interest, councillors toyed with the idea of hiring specialist consultants at a cost of $90,000 to better understand the CBD, including its market rentals and the impact online shopping was having on retailers. Councillor Brian McLachlan was against this.
"We've got experts right here in this town and we're ignoring them," he said. "We've got real estate agents all saying the same thing, shouldn't we be listening? Same with our landowners."
20/20 committee chairman Phil Halse instead moved that the council conduct a planning session with all councillors and report back to its full April meeting.
"We want to involve our local people. When you get buy-in, people back you," he said. He warned councillors not to over-congratulate themselves on the success of current projects and "keep [their] feet on the ground".