Loomis' one unforgivable decision
Without question, there must be consensus in the team building on how the team is built, and when and how to plan for the future. I have repeatedly described Payton during his years in New Orleans as our de facto general manager and given praise to Loomis for putting aside ego and developing an organizational process that accommodated Payton. Sean was heavily influenced by the experiences of his mentor Bill Parcells. In his first head-coaching job, Parcells battled often with Giants general manager George Young over personnel (and my memory is that more often than not Young's judgment was correct).
But at some point, the general manager, especially one like Loomis who enjoys a special relationship with the team owner, has to take a broader and longer-term prospective than a head coach like Payton who saw his Super Bowl window closing and emphasized winning now regardless of the long-term consequences.
Payton was the architect, and Loomis was the contractor who built what Payton wanted. My guess is that the Saints' personnel people graded Davenport highly, that Payton wanted Davenport almost regardless of cost, and that Loomis executed Payton's request, though he should have been more mindful of the cost. Unless Payton was willing to revamp his offense, picking Lamar Jackson in the 2018 draft made little sense. Certainly, if Payton had wanted Jackson, he would have been the pick.
My criticism of Loomis is that at times he surrendered too much power to Payton; that at some point he should have been assertive about building for the post-Brees era and finding our quarterback of the future; and that with Payton's departure, he should have moved in a very different direction, favoring a rebuild on some level, rather than the continuity approach that was chosen. Given how close Payton and Loomis supposedly were, Loomis must have known for some time that Payton wanted to leave.