I agree with most of what you said. Golden and Shannon were tenured too long, but there are reasons why.
Shannon coached 4 years from 2007-2010. In his first 3 years he went 5-7, 7-6, and 9-4. So, after his 3rd season, you think he has the program turned around, but then in 2010 the team goes 7-5 and Shannon is let go.
Al Golden coached at Miami from 2011-2015 taking over for Randy Shannon. In his first 3 years, Golden went 6-6, 7-5, and 9-4. Very similar to Shannon. In Golden's 4th year the team went 6-7. In his last season in 2015, Golden was fired after going 4-3 and the embarrassing loss to Clemson.
So, looking at both Shannon and Golden, ask yourself when should they have been fired? The only thing anyone could realistically say is that Golden should have been fired after the 2014 season. Both Shannon and Golden had 9-4 records in their 3rd year. Looking at it from an AD's perspective, you think these guys had turned the corner with the program, but didn't. And to be fair, Golden came in during the Nevin Shapiro scandal which had a huge impact on the program.
Looking at Dabo Swinney, he became the head coach at Clemson in the middle of the 2008 season when Tommy Bowden resigned. Dabo finished 2008 with a 4-3 record. He goes 9-5 in 2009. You think he's off to great start to his career, but goes 6-7 in his 3rd season. Should Clemson have fired him? Obviously, they didn't. He goes 10-4 in 2011, but suffers a humiliating loss to West Virginia 70-33. He rebounds in 2012 going 11-2 and never wins less than 10 games ever again. The rest as they say is history.
So, looking at the 3 coaches, Dabo had the worst record in his 3rd year and could have easily been fired. After all, he was just a WR coach of 4 years with zero head coaching experience prior to being named head coach at Clemson. If fired, Dabo could have easily been a Randy Shanon or an Al Golden. Clemson just got lucky taking a chance on a guy with zero head coaching experience in house.
Ironically, Manny Diaz is similar to Dabo Swinney in that they both became head coaches at schools they were on staff prior to their hire. Diaz had much more experience having been a defensive coordinator at several schools. Like Dabo, Manny is a good salesman. Is Dabo a better x's and o's coach. Probably not. Dabo has surrounded himself with very good people that have been with him a long time. He has established the culture he wants and is reaping the benefits in recruiting and titles. Let's see if Manny can do the same.
Looking at it all., IMO, we have just been unlucky the last 3 head coaches have all showed promise including Richt with his 10-3 2017 season. We have forgotten (maybe a good thing) how much the Nevin Shapiro scandal hurt the program. It allowed FSU, Clemson, Alabama, etc to plant a flag in our back yard. Now, we need to get them off our property. We do that by winning which will gradually get our top kids to stay home.
