public-private partnerships

I gave the following explanation to a friend who wasn't familiar with public-private partnerships (PPPs):
PPPs are basically like leasing a car, typically over a long time (15y) during which time the private partner (a for-profit business) rents it to the city and other users and runs concession stands to recoup his investment (with a healthy ROI, of course), after which the city takes it over (sometimes just in time for the building to fall apart). They're very convenient politically, because the city gets quick access to facilities for little cash down.
I am partially opposed to them on that same principle: I believe you shouldn't buy with money you don't have. However, the only usual alternative is for the city to raise money on the financial market by issuing bonds and/or debentures (effectively borrowing the money from investors who also seek a profit, but at least it is competitive), then having city staffers (already spread too thin) manage the construction, which is also far from ideal.