When I worked for the Braves, one of the things I felt/noticed/learned was how much clout the Braves have when it comes to drafting and signing players in the Atlanta area and in the Southeast region in general. It just seemed to me that more elite high school players in that region were willing to sign with the Braves out of high school than similar kids in many areas of the country.
The Braves obviously won 14 straight division titles from the early 90s into the mid-2000s. The success of the Braves created interest for elite high school athletes in the Atlanta area in being baseball players and not just SEC football or basketball players. Obviously the Braves have done a great job of mining their own backyard (including Alabama, North Florida, South/North Carolina, Tennessee) over the years (Brian McCann, Jeff Francouer, Jason Heyward to name a few known players) and yes, much credit can go to the development of the East Cobb baseball program but I dare say that program became so strong because of the interest the young players developed in the Braves and becoming future Braves.
All of the following high school players are from the general region I am speaking about, all were upper round Braves' picks and signed in recent years (back to 2000): LHP Brett DeVall (FL), RHP Zeke Spruill (GA), LHP Robert Stovall (AL), OF Jason Heyward (GA), OF Cody Johnson (FL), RHP Cory Rasmus (AL), LHP Steven Evarts (FL), OF Jordan Schafer (FL), C Jarrod Saltalamacchia (FL), LHP Matt Harrison (NC), OF Jeff Francoeur (GA), C Brian McCann (GA), LHP Macay McBride (GA), RHP Kyle Davies (GA), RHP Adam Wainwright (GA).
Could the Giants success and the Giants-mania (it really is crazy) lead to a generation of high school kids who grow up wanting to become Giants? Absolutely. It will need to be a prolonged run the Giants go on, to make that happen. A short 2-3 year stretch will not be enough to fuel a generation of kids who stick with it and want to be Giants. If it does happen, will those kids in the region be more willing to sign out of high school with their hometown team like kids in the Southeast and Atlanta area have with the Braves for years? I think it could happen, though not to the same extent.
For one, I haven't seen the Giants pay as much attention to their own backyard players as the Braves have done. That is not to say the Giants haven't drafted well recently, they just don't seem to bear down any harder on local kids vs kids from the rest of the nation. Part of the reason the Braves did so much with kids in their area and in particular, with kids from the East Cobb program and kids that played extensively in the Perfect Game tourneys that take place in Marietta (GA) every year (in Jupiter, FL too) is that former scouting director Roy Clark (now an assistant GM with the Nationals) lived in Marrietta and spent a bulk of the year at the East Cobb complex, seeing and learning about those players. He was like having another area scout in the area, the most powerful area scout in the big leagues.
The Braves Southeast (Georgia in particular) scouts (Al Getz and then Brian Bridges) in years past have spent an abundance of time at the complex all year and get to know the players VERY well. They nail their signability, they have been able to know they could take kids later in the draft or later in rounds than some other teams and still get those kids to sign with the Braves. A major difference is that the Giants west coast crosschecker lives in Arizona and they don't have a scouting director who treats his job almost like an area scout, like Clark did. There is a reason Jason Heyward slid to the 14th overall pick when he was largely thought to be one of the top few players in the draft. Thirteen other teams didn't so much pass on him, as I am willing to bet that he strongly passed on 13 other teams (he was signed to attend UCLA).
Granted, it seems that Northern CA kids tend to be more college focused than kids in many areas of the country so no matter how talented they are and have been, it has been difficult for any big league club to sign the best kids from this area away from schools like UCLA, Stanford, Cal, U of San Diego, Oregon State, Oregon, etc. The culture could change though and we might see it take place in this next draft. There are 3-4 high school kids in the area who could legitimately be taken in the top few rounds (Robert Stephenson, Joe Ross, Billy Flamion) and who knows, maybe they want to be Giants and might give the Giants a "hometown discount" they are not willing to give to another team. I think this year might be a little too early to see that effect, but if the Giants go on an extended run, I think we could see it happen with future generations.