There are three main reasons for why it is notoriously difficult to maintain success at Tech:
There are three main reasons for Tech not being able to sustain success after a great season: In no particular order
Recruiting, Recruiting, Recruiting. It is difficult as Wake, Rice, Tulane, Vanderbilt, SMU and others will attest to consistently recruit great players especially at certain positions. We have to rely on red shirting and player development which can be done but requires patience and absolute commitment to a system and targeting players EARLY. No easy thing to do. We simply cannot afford injuries, busts, or any combination there of. During Coach Johnson's tenure it has been a habitual struggle to find defensive linemen and offensive tackles. It is hard to find tackles that are big and can block in space. Generally, in my humble opinion, we can scheme our way on offense with lesser players but there is no amount of scheming that will work on defense. You just have to have the players on defense and we invariably end up with linebackers trying to become defensive linemen and quarterbacks trying to play safety or linebacker etc. It just does not work out too well.
You are correct that the problems are recruiting times 3 (or more). However, we can recruit better than we have for the past 7 years.
1. Many top teams have head coaches that are salesmen. For example, Dabo and Saban are salesmen. Johnson is not. That can't be fixed, but maybe Johnson could be coached up if he would allow himself to be. I'd argue that GT needs a head coach who is a salesman more than Alabama does.
2. GT has a national reputation and can recruit over a wide area, but it's not happening. I'd guess that about half of the 1990 2-deep was from more than 300 miles from Atlanta. I'd guess that 80% of Johnson's recruits are from within 300 miles of Atlanta. There aren't enough quality players that fit the academic profile to geographically restrict recruiting like this staff does.
3. GT has lots of advantages over other schools. Ever been to Clemson on a non-football weekend? What a depressing place. The GT campus is far nicer and more lively. We have lots to sell. However, we need salesmen. Roof and Pelton are a step in the right direction, but there have been too few recruiters on this staff for most of Johnson's tenure. You are seeing the results on the field.
4. Last year was an anomaly with regard to having few injuries, and there were some very good players who graduated. Anomaly is the key word here--like you can't count on that situation every year, and we don't have quality depth.
5. Lastly, O'Leary had 5 consecutive AP top 25 finishes from 97 to 01. I've posted that stat 3 times now in the last week, but people persist with this errant theme that we can't sustain success. O'Leary understood recruiting, saying that it's like shaving, if you don't do it every day, you look like a bum. Consistent good recruiting is the key to consistent performance--not play calling or scheme.