This doesn't apply to all the career sourcebook signature abilities, but a lot of them are pretty strange in that they seem to offer abilities that skilled characters ought to have anyway, without spending points on the signature ability.
For example, take the Commander's Rousing Oratory ability which costs 30 points:
Once per game session, the character may perform a Rousing Oratory action, spend 2 Destiny Points, and make a [difficulty 3] Leadership check to inspire a group to take action in a military situation about which members were previously hesitant.
Isn't this an ability that one ought to have anyway, if one rolls a good Leadership check? If a player with good Presence and 5 ranks in Leadership wants to rally a group of hesitant soldiers into fighting, should the GM really say "You can't do that, you haven't spent 30 points on Rousing Oratory"? And what's with the 2 Destiny Point activation cost on top of it all?
Does this seem as silly to others as it does to me?