Well, doesn't it require us to actually know what is in the bard's spell list before we can figure out whether being a "full caster" or "half-caster" actually matters? I mean... if Earthquake was on the bard's spell list, then "full" or "half" really doesn't make any difference at that point, because it's the spell itself (and not the amount) that is the issue there.
If people are associating "full caster" with "breadth of the Wizard's spell list!"... then sure, I'd understand their concerns. But that really can't be it, can it? No one actually believes that because the bard is "full caster" that the bard's spell list is now going to include all kinds of non-bard spells just to fill it out, do they? That seems like a jump in logic way too out there to believe.