In his 3rd full season as HC Clemson won 10 games and the ACC for the first time in 30 years
They also had one of the worst late-season collapses I've ever seen. They were in the conversation about the national title game and ranked #5, and then lost 3 of their last 4. And none of those losses were even close--they were all embarrassing ass-whoopings. The one win was a come-from-behind victory against a mediocre Wake Forest team, and even then they would have blown their shot at winning the division if FSU hadn't inexplicably choked at home against Virginia at the end of the season.
They seemed to have gotten the ship righted and looked good in the ACC championship game, but then put up one of the worst bowl performances in history. Clemson is the reason that Army's ridiculous showing this bowl season only tied the record for points scored in a bowl game.
If you just look at the number of wins and the fact that Clemson won the ACC in 2011, yeah, it looks like a great season. But that was basically a season-long example of Clemsoning, going 8-0 and getting to #5 when playing against the toughest part of the schedule, then looking like the worse team on the field in 5 of the last 6 games and putting up such a pathetic showing in the bowl game that they were making jokes about it on Game Day the next season.
At a school that hadn't seen a conference title in 20 years, that season was enough to take some of the heat off. At a school with actual real expectations, an utterly embarrassing late-season collapse a year after an abysmal showing might still have been enough to show him the door. Or a school that isn't in a soft enough division that you can lose 3 of your last 4 and still be in the running for a BCS bowl.
2011 cooled off some of the calls for him to be fired, but by no means all of them. A lot of people were very conflicted. I think it helped take heat off him when Kevin Steele ended up being the scapegoat for the Orange Bowl debacle, but that shit wasn't just on the defense. That was a complete teamwide meltdown, which is squarely on the head coach. Kevin Steele may have been the reason we couldn't stop West Virginia, but it wasn't the defense's fault that Clemson had 5 straight possessions in that game that totaled 14 plays for 1 total yard and two turnovers. That was an entire team just quitting on the coach in a major bowl game.
I will readily admit that I thought we'd seen the ceiling with Dabo around 2011-2014. Getting 10-win seasons because we only play 2-3 good teams in a year, being competitive in the conference, occasionally sneaking into the title game if FSU slips up or going to the Orange Bowl if the ACC champ plays for the national title or something. I was amazed that he managed to put together what he did in 2015, and I continue to be amazed that it has been sustained instead of just being a flash in the pan.
But, back to the main point, I'm not sure I agree that a team that really wants to be seriously competitive, and hasn't been starved for any success for two decades, would necessarily keep him around after 2011. That season hardly felt like "winning a title" so much as "Clemsoning it later than usual." An awful season followed by an embarrassing collapse and an 0-3 run against your biggest rival might not get you fired everywhere, but it could well get you fired some places.