He does, but he's also a talking head (paid to give an opinion) and talking heads live in the moment. They can go from being completely supportive of a player when he's coming off a near-MVP system to the player is just OK and shouldn't have been paid when a season is going poorly and that player is now out for the rest of the year.
It's always easy to make decisions in hindsight, especially when you don't have to take blame if it contradicts an earlier opinion.
Back when Dak got his extension, Jimmy said, “Like him or not, Dak is the guy. He will be the guy, he’s been great during the regular season. Everybody says ‘Well you gotta win playoff games,’ well give him a chance to win playoff games.”
He also said when asked what Dak needed to win playoff games, “Surround him with a better-supporting cast. I’m not sure about their running backs right now, but they’ve got some outstanding receivers, they’ve got a good tight end, they‘ve got a good football team, they’ve got a good defense.”