Bottom line, people are generally make decisions on rational self-interest. People will go to a Tech game if they see it as the most reward (utility in Econ speak) for their time and money (resources). There are people who get a massive amount of reward just from being at a Tech game, win/lose, sun/rain, cold/hot. Tech Football is a core part of your life and identity (lot's of you on this board).
For any school, most fans will go to a game if it's the best use of their time and money. For people who live their lives around their football team, all they need is the game, the rest is just background. The UGAs and Bamas have 10s and 10s of thousands of those fans. We have 10-20,000, tops? That level of fandom just doesn't develop overnight. It takes years of positive experiences to ingrain that commitment.
Being realistic; if Tech wants to fill the stadium, they have to raise the utility and/or lower the resource cost. For many fans the overall experience of staying home and watching on TV is the higher utility than going down to the game. For all the reasons people have mentioned: our stadium is hot and uncomfortable in the sun, the lines (for everything, entry, food, water, restrooms) are too long, concessions are mediocre and expensive, the on field product hasn't been great the last few years, etc. Not to mention things largely outside of Tech's control that detract from the experience; like traffic, parking, petty crime...
If gross attendance is Tech's goal (and I don't think it necessarily should be), then cut the costs of parking, tickets, concessions, partner with Uber, Lyft and Marta to give transit discounts, make the "cost" in time and money as low as possible. And a better experience would help too.
If the goal is maximum revenue (which is what I think it should be), then make the experience of going to the game much better. Lower the gross attendance goal and get more money from fewer fans for a premium experience. Make 75% of the stadium "club seating" and cut the capacity some. Install real (wider, more comfortable) seats, better concessions, some air conditioned areas in the concourses with TV monitors, sell alcohol, let people bring stuff in, look into installing sun shades, more overall staff to serve customers across the board...
Look at how much better the Brave's attendence has been since they moved to the new ballpark with a much better overall experience. It's a smaller park, but they're filling it up and making more money per fan.
Just for example: if we were able to fill the stadium with 45,000, that are paying 50% more for a better experience, we make ~18% more revenue vs a 55,000 sellout baseline. (Assuming the marginal cost of the experience improvement isn't prohibitive.) And I'd say make some of the upper stands walk-up $5 tickets for the "classic" experience.
(I'm an economics nerd)