He was a fatally flawed manager in the end that had a brief window of excellence. His inability to adapt will lead to him forever being a journeyman at best.
Moyes was all of the above things as well. They are much of a muchness. We can argue about how he 'solidified' us all we want. But in truth he was Tony Pulis or Sam Allardyce given free reign for 11 seasons. They also solidify teams, hit a glass ceiling and go no further.
Koeman currently has us where Moyes did.
We have the same inferiority complex that we've had since Moyes' heydey. We are incapable of stepping up when it matters, see Anfield; neither Martinez or Koeman has changed that one iota regardless of their other positives or negatives. If Koeman changes that, great. But Martinez was not the only thing rotten at Goodison, make no mistake - the mentality of perpetual failure continues to hang around like a bad smell, and if we ever achieve what we all desire that needs to be dealt with tout suite.
Martinez was a failure in large part because he couldn't change our assumption of failure.