Really? If anything I thought that it proved regardless of which animals gained a sentient capacity, they'd all end up at the same point.
They still naturally acted upon instinct but were also willing to go against it, if deemed worthwhile. (i.e. the king offering to spare Netero
I think if anything it both made the ants better villains but also somewhat more interesting by giving them human characteristics. It would have been more of a cop-out if they'd been evil because it was convenient.
If you honestly thought it was bad though, what would you have done, that would have improved it?