His teams have always played down to opponents, have a bad habit of overlooking opponents, and I can not think of the last game I was surprised that they won.
Also never having a losing season is kinda a meh stat since he has gone 8-8 3 times and missed the playoffs 5 times. The guy doesn't elevate his teams talent, his team's talent elevates him.
I would easily take BB, John Harbaugh, Andy Reid, Sean Payton, and Pete Carrol over him
I would strongly consider taking Kyle Shanahan, Sean McVay, Jon Gruden over him
I could be convinced to take Mike Vrabel and Brian Flores over him
So even if I place him before the third group that is the 9th best coach out of 32 so I would not consider anyone in that ranking very good.
Yes, they do have a habit of overlooking bad opponents. And yet, despite that, they've won 65% of the time over 14 years. As for being surprised that they won, they're 3-0 this year in games they tried as underdogs (TEN, at BAL, IND) and almost beat the Browns as 10-point dogs with their backups. They went 8-6 last year with Mason Rudolph and Duck Hodges. Does that not count as being surprised?
Let's for the purpose of your argument use non-winning seasons and missed playoffs during his tenure. The Steelers have had three and five respectively since 2007. Only the Pats have had fewer non-winning seasons while only the Pats, Packers and Seahawks have missed the playoffs fewer times and the Seahawks have a season where they got in at 7-9.
No one will argue against BB but let's take a look at the rest of these guys:
Harbaugh: The easiest comparison since they're in the same division. Won a SB but hasn't been to another. Two fewer division titles since he was hired. Regular season winning percentage 30 points lower. Missed the playoffs three years in a row and four of five from 13-17. Won one playoff game the last seven years.
Reid: There's obviously an argument for him but he's not perfect. Won one playoff game in nine years from 09-17 (against Brian Hoyer), which included going 8-8 with the "Dream Team" and then bottoming out the next year at 4-12 and getting fired. He's obviously a HOF coach that's one of the great offensive minds in history but it also helps to have possibly the most talented QB ever.
Payton: He's coached the same number of seasons (came in a year earlier but lost a year to Bountygate). Only one SB appearance. Lower winning percentage despite being in a much worse division. Five non-winning seasons including three losing seasons in a row from 14-16.
Carroll: This is one I can definitely see, although his winning percentage with the Seahawks is still lower than Tomlin's. Only missed the playoffs twice in 11 years, but one year he made it at 7-9.
As Super Nomario mentioned above, taking Shanahan and Gruden especially just doesn't even pass the smell test. McVay is a great coach but his offensive expertise got punked in his SB appearance and he didn't win a playoff game his other two years. Vrabel is a very good coach (especially knowing how to exploit the rules) but it's still too early. Flores certainly has Miami on the right track and they overachieved this year. They also just gave up 56 points with their season on the line playing half the game against Matt Barkley.
In addition, while Ben is certainly going to make the HOF it's not like he's some cheat code. He's never received a single MVP vote or even made second-team All-Pro.
This is just mostly all nonsense and I guarantee I hate the Steelers more than you do. Do you realize how inane of a position you have to take for me to defend them like this?