I have admittedly pounded Tomlin at various times for years. He did make some questionable in game decisions mostly due to inexperience.
Tomlin inherited a Super Bowl roster that Cowher built after he won the power struggle with Donahoe. After Cowher retired, Colbert took over much of the roster assembly that I believe Cowher had control of. His drafts left a lot to be desired and we were losing the Steelers way.
Since Khan has taken over his drafts have addressed things that Colbert ignored for years. Coincidentally Tomlin has suddenly become a much smarter coach. You can say what you want about Tomlin but it's pretty obvious players love playing for him. I also thought he did a great job guiding us through one of the toughest schedules in memory to get his Super Bowl. We'll see how this works out but right now I wouldn't want more than a handful of coaches other than Tomlin, and most of those would be questionable choices.