What they get for kickbacks is permission to build higher end, larger profit margin single family homes. Part of the whole mixed socioeceonomic classes thing. Put the low rent places in close proximity to the single family McMansions and the plebes (or more properly their kids) will see fruits of being a good student on display every day and make friends with the kids of those successful parents, and be motivated to work harder to earn those things.
You can see the results in Riverbay and Westbury.
That's driven at the State level, do a mix of housing and, when the County puts in requests for funding for schools, roads, sewer and water capacity, the approvals are easier.
Workforce or affordable housing, especially affordable, are the new names for subsidized housing. Section 8 had too negative a connotation.
Having said that, there is a need for housing that people who aren't federal employees or government contractors can afford. Don't be fooled by the relatively high median family incomes in Southern Maryland, that's skewed by a relatively few high income/wealth people.