City residents in recent years have thrown hundreds of millions of dollars at schools and parks with marginal results, and they have created a system in which lawmakers attain office with just 2 percent of the citywide vote and yet cling to the ideal that they will represent all of San Francisco.

Which brings us to our latest foray into the ballot box of the absurd, generally known as dueling Propositions F (as in fantasy) and G (as in gift), arguably among the most important land-use measures voters have seen in the past quarter-century. And, if recent polling is any indication, it appears that not only are voters prepared to look a gift horse in the mouth, they’re ready to smash said gift into a thousand broken pieces.

I have some faith that reason and common sense will prevail, but then I remember how, despite my best efforts, San Francisco elected Terence Hallinan — by any statistical measure the worst district attorney in California’s history — twice.

Proposition G is a policy measure that seeks to transform long-neglected Hunters Point Naval Shipyard and the Candlestick Point site into a new housing and park area with as many as 10,000 new homes, promises thousands of jobs for community residents and calls for the rebuilding of the run-down Alice Griffin housing project. It would also provide a permanent home for the remarkable group of artists who have been working in some very dreary shipyard studios for more than two decades, and it includes a provision that 30 percent of the new homes are built as affordable.

But the Lennar Corp., the private developer behind the housing plan (and also one for Treasure Island) has run afoul of some discredited activists in the Bayview who blame the company for stirring the existing asbestos at the Superfund cleanup site and have essentially portrayed Lennar’s officials as baby killers. To that end, they found a friendly ally in supervisor and resistance leader Chris Daly, who, unable to get the support of his colleagues on the board, launched a signature drive to qualify Proposition F for the June ballot — a measure that demands the developer increase the number of affordable units to 50 percent.

Now you don’t have to be a developer to know that a 50 percent affordable quotient is unprofitable, undoable and unthinkable — that is, if you actually believe that any private developer would even consider such a losing proposition. But that’s not what is happening here, for Proposition F is designed solely to kill the Hunters Point development project — an unmistakable poison pill marked up with a happy face.

Proposition G has taken 10 years of design studies and hearings just to get to this point. It has the support of Mayor Gavin Newsom, Sen. Dianne Feinstein and most every considered planning organization in San Francisco. The one hiccup with the measure has been the lack of support from unions, which are demanding more work force housing for teachers, service employees and other municipal workers — though I’m told ongoing negotiations may produce a positive outcome soon.

But if Prop. F passes, and recent polls suggest it could, it would kill the Bayview development plan and leave a community that is deficient of jobs and housing once more in search of tomorrows that never come.

I asked Michael Cohen, the widely respected head of the Mayor’s Office of Economic and Workforce Development, how big a setback it would be if Prop. F is approved.

“If there’s a 50 percent requirement for any private developer on a project like this, it will ensure that that land will remain fallow for the next 20 years,” he said.

So you’d have to wonder why activists who reportedly support the poor and the needy would try to detonate a long-studied plan with a last-minute proposal that has no details or financial analysis. Part of the answer could be found in a plan by Daly probably headed for the November ballot in which the free-spending supervisor wants to set aside $2.4 billion in taxpayer money from the general fund over the coming years to spend on affordable housing.

That’s not a land grab, it’s a revenue raid — and an untimely one at that. I don’t know about you, but I’d rather have a private developer cover the cost of new housing than our deficit-straddled city, especially a builder that is willing to commit at a time the home-construction market is in the tank.

The Bayview community deserves some equity — and some hope. For residents there, Prop. F stands for just one thing: Forget about it.