Mike McDaniel's.
The way "a team takes on the personality of its coach" as they say is by determining the kinds of players who are likely to become leaders and thereby shape the culture of the team via the effect of their leadership on their teammates. If your head coach is a goofball, players like Hill and Wilkins are likely to rise to the stature of leaders and will feel permitted to lead their teammates from that angle -- i.e., fun and games and elaborate and rehearsed end zone celebrations.
If on the other hand your head coach is the gruff and tough Bill Cowher for example, players like Joey Porter and Jerome Bettis are likely to become player leaders and lead with toughness and physicality. If your head coach is the serious and cerebral Bill Belichick, someone like Tom Brady is likely to become a key player leader and lead in that vein. The head coach's personality essentially "prescribes" the kind of player leader who's likely to rise to that stature among his teammates.
McDaniel has to start by being less of a goofball. Toughness and physicality (Cowher's Steelers), as well as a serious and cerebral approach (Belichick's Patriots), are consistent with winning in the game of football. What's not consistent with winning in the game of football is a goofball fun and games approach that can't become serious when the need arises, and the need arises very frequently in the NFL.
The team is soft because McDaniel is soft, and because the leaders among the players follow his lead.
Here is the opposite of that:
That Steelers team was the lowest-seeded AFC playoff team and won three playoff games on the road as an underdog before winning the Super Bowl as a decided underdog against the top-seeded team from the NFC. If you don't believe the kind of team culture and player leadership seen in the video above was the prime mover in that extremely rare accomplishment, I don't know what to tell you.
