I think part of the problem has been that they've been cheap and lazy about building the defensive staff. I remember that when we were on the Rivals board, a lot of people wanted Phil Bennett. From what people were saying on there, TTU didn't want to pay coordinator money for a coordinator, so we went with a guy named Glasgow from TCU that everyone hated who only lasted a season. As far as I know they continue to do the same thing, hire people who are underqualified because the school doesn't want to pay coaches.
Not many schools can go after the hired guns on the defensive side of the ball. Tech wouldn't be a destination school for such a coach either. It is not as easy as simply dialing up the best guy out there and throwing some money at them.
It goes back to a few things that caused the problem.
Leach didn't care of defense. He only had a few competent defenses over the years. That pretty much set the tone for many years to come. Most schools that hit on a big year follow it up with strong recruiting at a push for expansion. Leach literally quit on the team after his big season. He stopped recruiting and began for using on other jobs.
Once leach was fired we brought in dumbo Tubs who turned out to be the absolute worst hire. That dipshat did nothing but set the program back with a terrible attitude. He couldn't hire a defensive guy to save his life. You are right about Glassgow in a way. He seemed like a smart hire because he was the top assistant at the best defensive school in the state. That dude was a mess, the next guy was fired for beating his wife. He was the LBer cosch from Alabama. So we have a string of failures:
2009 Ruff McNeil - left when Leach was fired. Now the head coach at East Carolina
2010 Dude from Alabama - fired for beating his wife
2011 Glassgow - top tcu coordinator fired for being a total nut job with a possible mental disorder
2012 Art Kaufman - respected coach from North Carolina that left when Tubs quit. He seemed solid and tried to get the mess back on track
2013 Wallerstadt - fired for coming to work high on something several times. He seemed like a competent coach. He was a LBer coach from aTm
2014 Mike Smith interim - Rex Ryan's pet assistant. He's been with Rex for several years and is very respected in the NFL. He knows his stuff well. He's been offered more NFL jobs since he's been there. If he stays he has a mess to clean up that will take multiple years.
One thing about being a college head coach that people glass over is the network that coaches bring. Kliff essentially has none. He hasn't built a network yet so he basically doesn't have anyone to reach out to. He is also a loner who keeps to himself. Young pride probably has bitten him some. He definitely will need to grow to make it. When Kliff came he spent a bunch of time trying to build a defensive staff. He had the dude that is the coordinator for Wisconsin on the hook until his old coach called him and stole him away at the last moment. Tell me this, would you rather come to a program that is historically bad on defense or go to Wisconsin to be a d coordinator? Can you blame the current tech staff for that? I don't know.
As far as hiring someone like Phil Bennett goes, that dude flunked out at smu as a coach and has never had any kind of ranked defense over at Baylor. Nobody says anything because that program is stable and wins lots of games. They haven't done anything amazing on that side of the ball.
I don't care who you hire this year the defense is going to suck. There are no players. None. Any player with any grit is 18 years old and can't lift a paper towel. Don't think folks understand that we literally had 4 18 year old kids starting on defense last night. They are the best that we have. The rest are JUCO players who were rejected from other places. They are basically retarded and cannot play.
It is a total mess right now. The answer isn't to hire some other coach right now. He won't be able to do much. Stability is the #1 priority.