Tbh Mexico has been consistently in the top 16 for close to 30 years (enduring the natural up and downs that plague any team, at any given moment). Unfortunately, they'll likely never make the permanent jump into the top 8 - which is what they need to do to improve their chances at winning a major tournament. In the top 8 ANYTHING can happen as LUCK has as much to do as any other factor.
I felt that Mexico drew the short end of the stick in the last WC against the Dutch - who didn't deserve to win their respective round of 16 match against them. I don't feel bad cheating Robben is left out of the upcoming WC.