Well Itachi was a pretty misunderstood character. Zeref might be the same.
We all know that Zeref "respects" life which is the reason for his curse. Its kinda similar to Itachi's feelings.
Both were prodigies.
I still see a lot of similarities.
I'm really not seeing it though. With Itachi, everything he did was for his village and brother. All the "evil" everyone thought he was was fabricated for the village's sake.
With Zeref, he started out acquiring forbidden knowledge for good means ( Natsu) but in the end, as nice, and "respectful" Zeref claims to be, we all know his pursuit in this ultimately corrupted his way of thinking and he got himself cursed doing so. Nothing he does is for the good of the people. The terror people feel for him is real and not fabricated like Itachi.
In other words, Itachi was a genuinely good guy. Zeref was but is now corrupt and dark.