The complete disrespect some Saints players showed to the club off field would be another factor.
When the money offer came around then that would be a factor...."why should I stay here if the players are willing to derail season after season with their own stupidity"
You mean the NZ incident?
I actually thought Lyon took a bit of accountability for that one, I remember him doing an interview where he admitted he hadn't thought of the mindset of the younger players and how they coped with pressure at an AFL level.
I also thought he owned that dismissing the AFLPA organised counselling sessions as irrelevant was probably an error on his part, and also introduced a system whereby the younger players were required to work to keep them motivated.
Everyone makes mistakes, everyone can learn something, even coaches.