Fighter is a poor example into it's self. PS covers CL loss as a Wizard/Warblade/JPM which nets things like concentration checks instead of saves & concentration checks (with multipliers) to damage (without using the limited spell slots). PC also can cover Bard dipping to pick up Dragonfire which can be augmented to the entire party & all summons gain +12d6 acid per attack by the 8th level. Name a spell that comes half as close to that.
As briefly mentioned by your self, what you want to do trumps what someone else whats you to do. Vast majority of people don't play StP Erudites and choose a lesser class, such as a pure wizard for example, it doesn't mean they are wrong. In fact, if everyone else is disagreeing with you, it's a huge sign you're the one not thinking things though.