The Diamondbacks came into the season with the express intent to be competitive. Exactly what being competitive means has different definitions for different people. For me, being competitive ultimately means being able to compete for a Championship. However only one out of thirty teams will be the Champion, and only two of them will play in the world series.
The odds are long that any team will be one of the last two in any given season, even for the “favorites”. The very best teams on paper seldom enter a season with more than a 15-20 % chance of winning the world series.