Let me strengthen the claim, then.
In the limited number of minutes Enes Kanter was on the floor this season, he was an above average defender. In other words, there is no need to speak of the future tense. I think it was his offense that restricted his time on the floor.
I know in March he ranked in the bottom 16th percentile in post defense, according to a Grantland article. Not sure if it improved since then, but either way that is pretty bad and certainly not above average. Like I said he did a good job showing on the ball handler in Pick n' Rolls, but that is about the only thing I really felt he did a good job of defensively. That is a pretty good sign though and a big strength if it isn't just a fluke, but it doesn't warrant a tag of "very defensive minded big".
Again, not say can't or won't improve, but I just can't call him a defensive minded big. I don't really see how that is a "haterism" as much as it just being realistic.