How would that fix anything? Are now "enemies" somehow a different race/species? Is that a new term for "NPC?" Why can they know a technique/method/power that it is impossible for a "non-enemy" to know/have?
Maybe I can give you a better response if you can explain to me why you think the statblock saying "Abjuration Enemy" would make it better.
Then why do you need to remove it from the race in order to play one that doesn't have it? And, er, isn't the default setting going to have everything but PCs of those races having the trait, since only the PC entry for those races lacks it? Do you seriously not see how that pretty much states that the PC "race" is not the same thing as the NPC "race?"
Or, perhaps I again am misunderstanding you. What are you saying I'm viewing, in your perception, as a "shackle," and, if so, how does that not also serve as an argument why the change was a bad idea/unnecessary?