Been there done that. I think the idea is to change the "tours" into legitimate tours.
Here is how I see it:
Sweetwater offers "tours" on Wed - Fri, you give them $X for a glass (I think the "tour" is technically free). You get so many tickets for "tastes" during the tour. [Almost] no one goes on the tour (or realizes that there is one for that matter). People hang out drink and listen to the live music.
Essentially the brewery is "selling" their beer to people on the "tour" since most people think they are paying for beer when they buy the glass. They make a lot of money this way since they don't have to give any cut to the distributor/bar.
The bars in the area get pissed since they have to pay to maintain a liquor license and Sweetwater doesn't. They complain to the distributor who has a lot of political clout and get the rules changes.
I don't think these rules have any effect on the number of breweries in Georgia. Georgia is not a beer state. Can't sell alcohol on Sundays, the governor like most of the north part of the state believe that drinking is a sin.
Compare Georgia to its neighboring states (Alabama, South Carolina, North Carolina, Tennessee) none of these states boast a huge number of breweries and IMO it is not because of the laws but because the political and religious climate are not supportive of beer culture. In Colorado "if you brew they will drink," not so in the Southeast.
EDIT: I guess they do charge admission to the tour, I thought it used to be free as I remeber people refusing the glass and getting plastic cups for their tastings.