Often we say a person reverts to Islam, since
...we all have a fitrah (innate nature) to the values of Islam, because we are all born as Muslims. -- ashes999, in answer to Why are converts to Islam called reverts?
At the same time, we are forbidden from imitating non-Muslims (or disbeliever, or kafir). There seems to be some level of incompatibility between these two notions: how can we imitate a non-Muslim when they're innately Muslim anyway?
Question: How is the notion of a "revert" compatible with not imitating non-Muslims?
I'm tempted to think that "revert" is meant as an unessential nod towards the idea of fitrah, and is not intended to be taken too literally. I don't recall seeing it directly mentioned in the Qur'an or Hadith (but maybe I missed it).