Is it just me or is there a curse for the good coaches in Mexico? they always seemed to get fired before their cycle is complete or before they are able to achieve something. For example Galindo, he had the team playing exciting futbol and you know Chivas was bound for great things, then he gets fired out of nowhere because of the caprichos of Vergara. We also have Carillo who won a championship with the team, had the team playing good futbol and he gets screwed by Lapuente it seems and Lapuente takes over. Westerhoff in his first at charge of Chivas saved the team, got them to the final with a very limited team but with exciting futbol, but they make him leave after getting to the final (doesn't matter if Galindo was taking over or not). We have Benhakker who became a legend in 94 in America without the directiva even allowing him to finish the job, then he comes back a second time and they don't let him finish the job again! It just seems that in Mexico good coaches who have their teams playing well and have the potential to do great things never seem to finish the job because they aren't allowed to. But guys like Arias, Ferretti and others always find jobs they seem to stick around forever.
Ferretti & Arias always end up coaching for (arguably) less important clubs where the stakes aren't as high; the only examples you gave were from America or Chivas; Another good example would be Ruben Omar Romano, who had Cruz Azul playing great football, was kidnapped and held hostage and ended up getting rewarded with a dismissal. Again, however, Cruz Azul is one of the country's "biggest" clubs.
i wouldn't call it a curse. i would call it impatience by directivos and the torneo corto format - you get a bad streak and you're out of the liguilla, and possibly a job. it's a general pattern.