This sounds like another facet of a debate I think of as "Roleplaying" vs "Making Crap Up".
Roleplaying means you're living in a world created by someone else and are roleplaying as a character within that universe. This means that if you are a Klingon in Star Trek, you are a warrior with a racial superiority complex. You can roleplay it however you like, so long as you are basically Klingon.
Making crap up is when you go into a well established world and do something entirely outside the story of that world. You're no longer roleplaying in the traditional sense and are simply making crap up. It's like a D&D player simply telling the GM that he has a laser gun. He has stopped roleplaying and started making crap up. Similarly, being an alien in the KDF is basically making crap up. Playing a Klingon with the name "Daisy" who only talks of love, peace and smoking pot would also be making crap up.
"Telling your own story" can be entirely contrary to and destructive of real rolelaying.
While I tend to agree with you, I'd rather have the kind of freedom we do now than having to live by someone else's draconian definition of what it is to be Klingon (for me Worf would not be Klingon where for someone else he might be the epitome).
What has started to annoy me the most though is the fact that I can't even get my own f'ing crew on my bridge. Seriously is there something so special about the code to do this that it must remain a Fed only thing?