In a movie, when we look at people carrying out various actions, saying various things, and we come up with our own interpretations about who they are, what they are like.
Yet later on in the plot, something key is revealed about them... And then we go... "Oh... I know what he meant know", or we begin to reinterpret what they said or did previously by what we now know.
This of course does not imply that the character has changed, but that our understanding of the character has changed.
This does not imply that those things were not already there in the text, but rather we did not see those things, until someone made it clear to us (it may have been clear to someone else)
So then the fault is with what we understand, not what is written
Accusations of "you're reading too much into it" could just as well be confessions of ignorance or a lack of depth of relationship with Christ