Yet Quicken Loans, the mortgage lender Gilbert co-founded in 1985, has invested $1 billion over three years, bought some 2.6 million square feet of commercial space in the downtown area and moved 7,000 employees there in a bid to make that vision a reality.

The company is in talks with 80 to 100 retail outlets and restaurants to open downtown space, and Gilbert and other business leaders have fronted most of the money for a $140 million light rail line in the heart of the city. Quicken has also invested in an incubator for technology startups, which now number 17.

Gilbert, who grew up in a Detroit suburb, wants to brake the exodus of educated young people from the only state in the country that lost population between 2000 and 2010. Among those who set up home elsewhere in recent years are two founders of daily deal marketer Groupon Inc, University of Michigan graduates from the Detroit area whose startup took root in Chicago.

"Young people are fleeing the state and we need to give them a reason to be here," Gilbert, 51, said in a recent interview in the Madison Theatre, one of many buildings his firm has bought.

Part of his zeal comes from his own need to attract top talent to Quicken Loans, which runs a nationwide online lending business that Gilbert says makes it "a tech company that happens to sell mortgages." Having avoided the subprime mortgages that crippled many of its competitors in the housing crash, the company has grown rapidly in recent years.

Quicken Loans moved downtown from the suburbs in 2010. Home loan volume went from $30 billion in 2011 to $70 billion in 2012; Gilbert sees it rising to $100 billion this year. He anticipates Quicken will surpass JP Morgan Chase as the country's No. 2 retail home loan provider during this quarter.

The company gives employees who buy property in the city a gift of $20,000 on condition they live in the city for five years. Residential real estate occupancy rates in the downtown and midtown areas are close to 100 percent.

That's helping to fill in the public services, cut as part of Detroit's attempt to stave off bankruptcy. Quicken has installed cameras and hired security teams to ensure employee safety.

'DE FACTO RACISM'

Gilbert's deep pockets have their detractors. In a recent op-ed in the New York Times entitled "Detroit, the Billionaire's Playground," author Mark Binelli said residents worried that Michigan may install an unelected emergency financial manager to fix the city's finances "shouldn't forget the ways in which power has already been ceded to an unelected oligarchy, whose members might, no matter how ostensibly well intentioned, possess questionable ideas about urban renewal."

There is also some criticism that the downtown redevelopment is creating an island of prosperity detached from the city's black inhabitants, who make up 83 percent of the population.

Hard data does not exist for the racial makeup of downtown, but it is generally whiter and wealthier than Detroit's poor neighborhoods. "We're focused on downtown - that's where we can make a difference," Gilbert says.

While there may be security and other menial jobs for Detroit's African American population downtown, Mayor Dave Bing, who is black, says the city needs investment in retraining and educating workers who in the past held automotive or manufacturing jobs for jobs in the city's new economy.

For others, the focus on downtown is a slap in the face for Detroit's poor blacks. "This is de facto racism," said Pastor D. Alexander Bullock, a local leader of Jesse Jackson's Rainbow PUSH Coalition. "There is clearly a plan to invest in the downtown area, but there has been no urban reinvestment in poor black neighborhoods."

Mayor Bing, who is cutting spending to try to avert the state's takeover of the city's dismal finances, is grateful for the assist.

"Downtown is coming back very strong, and that has been driven by the private sector," he said.

Sarah Brithinee, 26, is one of those who sees a "land of opportunity" in her hometown of Detroit, the opposite of the crowded marketplace she found during three years in Los Angeles.

Having returned in 2011, she is chief executive of Wedit, which rents out digital cameras for wedding parties, then edits the footage into commemorative videos.

"I feel for the first time in my life I am making a real difference by coming back to Detroit," Brithinee said.

Gilbert's father and grandfather both owned businesses in Detroit before much of the city's white population began moving to the suburbs 80 years ago, where there were federal subsidies for land. That exodus accelerated after race riots in 1943 and 1968 and was compounded by the slow decline of automotive jobs.

On the walls of some of the office space Quicken has taken over in Detroit there are giant black and white reproductions of photos of the city in all its glory, a hustling, bustling city with a dynamic core.

For Elizabeth Rose those images are part of her childhood in the 1960s when her father worked as a mortgage banker in the First National Building downtown, a building Quicken Loans now owns. Rose runs the first branch of coffee emporium Roasting Plant outside New York on the ground floor, where beans are piped up from the basement and roasted.

"For me, coming back was all about Quicken Loans and the commitment they have made to Detroit," Rose said. "I wouldn't have come back if they weren't doing this."