I have no problem with the game attempting to make classes balanced and actually wish WotC would put MORE effort into balancing the core classes and prestige classes they produce in their splatbooks. One of the most frustrating things I've found when playing D&D 3.x is that after ca. 2002 (when most of the 3.0 splatbooks had emerged) it became increasingly more difficult to play a straight, single-classed character and be as effective as another PC with prestige class levels.
With the advent in 3.5 of the extra core classes and expanded prestige classes, the problem has only worsened.
With the advent in 3.5 of the extra core classes and expanded prestige classes, the problem has only worsened.