It seems like this whole offseason has just been a series of free agents flirting with signing with the Giants before deciding they don't really want to come here. Pablo Sandoval and Jon Lester are the two biggest names, of course, though Melky Cabrera was reportedly offered a 4-year deal, and since there's no evidence that the offering team wasn't the Giants, it's a pretty safe assumption that he was the latest guy to say "It's not you, it's me" while crossing his fingers behind his back. So why doesn't anyone want to play for the Giants?
The fans aren't good enough
Sure, the Giants have sold out every game for years, with fan engagement high even in a miserable 2013, but that doesn't really count. The Fan Quality equation actually looks like this:
Fan Quality equals Fans Per Game times Ballpark Crappiness divided by Weather times Bandwagoners to the power of Good Food Stands. You can tell that the Giants have too many bandwagoners and too much good food in the stadium. Combine that with the weather being good year-round and a nice stadium, and obviously we as fans are awful. I wouldn't sign here either.
They hate everything about the city
It's well known that California's state income tax is overly onerous, in that it exists. Free agents who earn more money than they'll ever know what to do with can't stand the thought of losing some of that money to pay for dumb California things like redwood trees and kale farms. In addition, San Franciscans are total snobs about what you can call San Francisco. A lot of these free agents have been calling it "San Fran" or, yes, even "Frisco" for years. They worry that they'll be ostracized if they slip up even once, which is a legitimate concern. After all, Edgardo Alfonzo called it "Frisco" two days before he played his first game as a Giant, and he never recovered.
The Giants have already won their allotment of World Series for decades
It's simple math, really: since there are thirty teams, then every team should win one World Series every thirty years. The Giants, having won three since 2010, aren't due for another until the year 2100, well past the ends of the careers of everyone in the majors, barring a Jamie Moyer comeback. So what kind of player would even want to sign here? One who doesn't care about winning, and that's not a guy that we even want.
Unless he can play third base.
They don't want to play in the shadow of Buster or Madison
Buster Posey and Madison Bumgarner are big stars who have each won lots of hardware, several rings, and are widely beloved in San Francisco. If you're anyone else, there's no way to compete with that. Sure, David Ortiz has three rings, but he won't be around forever. And when he's gone, that's when Pablo gets to be the star. It's a similar story in Chicago, where simply not being Edwin Jackson will win Jon Lester at least three years of unquestioned approval. The Giants can't offer that. All they could bring up was a legacy of success and a great pitching coach and a pitcher's park and a willingness to spend a lot of money. In other words, nothing.
Better opportunities elsewhere
How could Jon Lester deny himself the chance to bring the Cubs their first World Series title in more than a century? And Pablo, of course, desperately wanted to be in a large market so that the local media could build him up into a hero before viciously tearing him down at the first opportunity, after which he could be traded and have a heinous smear job run against him in those same local papers. San Francisco just can't compete with that. The team's already won several championships lately, and brutality-wise, Scott Ostler calling you a knucklehead just can't compare with the Globe.
They don't want to be within fifty miles of the 49ers
Okay, yeah, that's fair.