Quote Originally Posted by AssertnFailure
Seems kinda weird for Deidara to suddenly have a hatred for sharingan when he seems so content around Itachi, and didn't make any reference to it when he fought Kakashi.
Even though his art lost to Itachi's art, he never actually admitted Itachi's art is better. He realized it for a moment then went into denial. Living that lie he had no reason to hate Itachi from then til now.

Then page 15 you see Deidara continuing his denial up until the "Not to Not to...Ugh" line. That was the exact moment Deidara finally admitted Sharingan is art and now he's going to go out in a work of art(s).