Because government bureaucrats need to be let in on the take to make it worth their time. Graft is how that gets done. Otherwise they usually just stonewall housing.

Paying $1 to government shills and corrupt capitalists for every $1 spent on actual housing is still a hell of a deal compared to not being able to build anything, which is the status quo in many locked up parcels. A moral standoff and resting on your principles of not funding graft sounds nice, but doesn't accomplish anything.